A323915 a(n) = A023900(A005940(1+n)).

1, -1, -2, -1, -4, 2, -2, -1, -6, 4, 8, 2, -4, 2, -2, -1, -10, 6, 12, 4, 24, -8, 8, 2, -6, 4, 8, 2, -4, 2, -2, -1, -12, 10, 20, 6, 40, -12, 12, 4, 60, -24, -48, -8, 24, -8, 8, 2, -10, 6, 12, 4, 24, -8, 8, 2, -6, 4, 8, 2, -4, 2, -2, -1, -16, 12, 24, 10, 48, -20, 20, 6, 72, -40, -80, -12, 40, -12, 12, 4, 120, -60, -120, -24, -240, 48, -48

Offset: 0

Author

Antti Karttunen, Feb 22 2019

Keywords

• sign

Links

• Antti Karttunen, Table of n, a(n) for n = 0..16384
• Antti Karttunen, Data supplement: n, a(n) computed for n = 0..65537
• Index entries for sequences related to binary expansion of n

Crossrefs

Cf. A005940, A023900, A290077, A324052, A324054, A324055, A324057, A324058.

Programs

PARI

A323915(n) = { my(m1=1, p=2); while(n, if(!(n%2), p=nextprime(1+p), if(1==(n%4), m1 *= (1-p))); n>>=1); (m1); };

PARI

A005940(n) = { my(p=2, t=1); n--; until(!n\=2, if((n%2), (t*=p), p=nextprime(p+1))); t }; \\ From A005940
A023900(n) = sumdivmult(n, d, d*moebius(d)); \\ From A023900
A323915(n) = A023900(A005940(1+n));

Formula

a(n) = A023900(A005940(1+n)).