# Mathematical cryptic clues

1. Programming language, after removing loss for you, reverses time (6)
2. Complex arithmetic begins, Turing tests start beforehand (7)
3. Quadruply male doctor Einstein, familiarly (11)
4. Lie on a 100/100 imaginary item (9)
5. Between 3.14 and 2.718 is originally risky mathematics (5)
6. Arctan maps every other arccot into an embankment, too (8)
7. Heated rant with part of Ulam spiral (7)
8. Curse without Germain’s initial initial (4)

Solve these cryptic clues (no definitions), then find the answer to this question: what role does math play in our daily lives?

Remember: when in doubt, always consult OEIS!

• 5 on the list makes me think of pie. – Mr Pie Apr 6 '19 at 9:21
• @user477343 of course, you’d know all about that ;-) – HTM Apr 6 '19 at 9:22

By the time I posted this (in an incomplete state, though it's done now) others had also solved the first 5 clues. I shan't reproduce those solutions here. Here are the last three.

Arctan maps every other arccot into an embankment, too (8)

ABUNDANT. (Take the word ARCTAN. Replace RCT, found as alternate letters of ARCCOT, with BUND, a type of embankment. Then add T, which I guess comes from "too" in the clue though I don't quite understand how.)

Heated rant with part of Ulam spiral (7)

NATURAL. (Anagram of RANT ULA).

Curse without Germain’s initial initial (4)

PELL. (SPELL without the initial letter Sophie Germain's first, i.e., initial, name.)

So, what's next? Well,

all the answers are names of particular sets/sequences of integers, and the question directs us to OEIS. And of course we have those italicized words. I confess that before doing what I'm about to describe I tried a couple of other things that incorporated most of the right ideas "but not necessarily in the right order"; a helpful hint from OP in the comments set me on the right track. So: take the position of the italicized word in each clue, and use it to index into the corresponding sequence of numbers. In some cases there's more than one possible convention as to where to start; following the advice in the puzzle we'll use the version in OEIS. We get (SQUARE:4) 9, (CATALAN:5) 14, (TETRAHEDRAL:5) 20, (FIBONACCI:6) 5, (PRIME:4) 7, (ABUNDANT:2) 18, (NATURAL:1) 1, (PELL:5) 12, mapping via A1Z26 to letters I N T E G R A L.

So clearly the answer is, appropriately enough, that

mathematics is integral to our daily lives.

• The two cryptic clues you got are right! – HTM Apr 7 '19 at 2:40
• Very good! My best for clue 6 was COSECANT but too loose a fit. – Weather Vane Apr 7 '19 at 11:38
• Awesome, you answered the question correctly! Regarding the “too,” rot13(V arrqrq n jnl gb pyhr n G, naq nyy V pbhyq guvax bs gb nppbzcyvfu gung jnf gung jbeq, juvpu vf n ovg vssl ohg V pbhyqa’g guvax bs nalguvat orggre). Your green check mark will arrive within 1-2 business days :) – HTM Apr 7 '19 at 18:42

No time to finish, but a partial...

2. Complex arithmetic begins, Turing tests start beforehand (7)

C(omplex) + A(rithmetics) + T(ests) + ALAN (Turing) = CATALAN

3. Quadruply male doctor Einstein, familiarly (11)

TETRA (quadruply) + HE + DR + AL(bert) = TETRAHEDRAL

4. Lie on a 100/100 imaginary item (9)

FIB (lie) ON A C/C (100/100) I (imaginary item) = FIBONACCI

5. Between 3.14 and 2.718 is originally risky mathematics (5)

PI (3.14) + E (2.178) with R(isky) M(athematics) inside = PRIME

• These are all correct! – HTM Apr 6 '19 at 17:10