1,4

Antti Karttunen, Table of n, a(n) for n = 1..10000 (based on Hans Havermann's factorization of A156552)

Index entries for sequences related to binary expansion of n

Index entries for sequences computed from indices in prime factorization

Index entries for sequences related to sigma(n)

a(p) = 0 for all primes p.

(PARI)

A156552(n) = {my(f = factor(n), p2 = 1, res = 0); for(i = 1, #f~, p = 1 << (primepi(f[i, 1]) - 1); res += (p * p2 * (2^(f[i, 2]) - 1)); p2 <<= f[i, 2]); res}; \\ From A156552 by David A. Corneth

A324815(n) = bitand(2*A156552(n), A323243(n)); \\ Needs code also from A323243.

A324820(n) = { my(v=0); fordiv(n, d, if(issquarefree(n/d), v=bitxor(v, A324815(d)))); (v); };

Cf. A156552, A323243, A324815, A324821, A324878.

Sequence in context: A272203 A324815 A019200 * A337996 A087604 A090538

Adjacent sequences: A324817 A324818 A324819 * A324821 A324822 A324823

nonn

Antti Karttunen, Mar 18 2019

approved