A324339 a(n) = A246707(A005940(1+n)), where A005940 is the Doudna sequence, and A246707 is the expansion of phi(-q) * phi(-q^2) * phi(-q^3) * phi(-q^6) in powers of q.

-2, -2, 2, 6, 4, -14, -2, 6, 0, -12, -4, 42, 2, -50, 2, 6, -8, -16, 0, 36, 0, -84, 4, 42, 14, -62, -2, 150, -24, -158, -2, 6, 4, -24, 8, 48, 16, -112, 0, 36, 0, -96, 0, 252, 0, -300, -4, 42, -10, -114, -14, 186, -28, -434, 2, 150, 0, -312, 24, 474, 38, -482, 2, 6, -4, -28, -4, 72, -8, -168, -8, 48, 0, -144, -16, 336, 8, -400, 0, 36, 16

Offset: 0

Author

Antti Karttunen, Feb 23 2019

Keywords

• sign

Links

• Antti Karttunen, Table of n, a(n) for n = 0..1505
• Index entries for sequences related to binary expansion of n

Crossrefs

Cf. A005940, A246707.

Cf. also A323915, A324335, A324336, A324340.

Programs

PARI

A005940(n) = { my(p=2, t=1); n--; until(!n\=2, if((n%2), (t*=p), p=nextprime(p+1))); t }; \\ From A005940
A246707(n) = { local(A); if( n<0, 0, A = x * O(x^n); polcoeff( eta(x + A)^2 * eta(x^2 + A) * eta(x^3 + A)^2 * eta(x^6 + A) / (eta(x^4 + A) * eta(x^12 + A)), n)); }; \\ From A246707
A324339(n) = A246707(A005940(1+n));

Formula

a(n) = A246707(A005940(1+n)).