A328831 Number of distinct prime factors p such that p^p is a divisor of n-th number > 0 that is a sum of distinct primorial numbers, A276156(n).

0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 2, 0, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 2, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0

Offset

1,20

Links

Antti Karttunen, Table of n, a(n) for n = 1..65537

Index entries for sequences related to binary expansion of n

Index entries for sequences related to primorial base

Formula

a(n) = A129251(A276156(n)).

Prog

(PARI)
A129251(n) = { my(f = factor(n)); sum(k=1, #f~, (f[k, 2]>=f[k, 1])); };
A276156(n) = { my(p=2, pr=1, s=0); while(n, if(n%2, s += pr); n >>= 1; pr *= p; p = nextprime(1+p)); (s); };
A328831(n) = A129251(A276156(n));

Crossrefs

Cf. A129251, A276156.

Cf. A328832 (gives A276156(k) for those k for which a(k) = 0).

Sequence in context: A086076 A334348 A316717 * A085981 A243224 A127324

Adjacent sequences: A328828 A328829 A328830 * A328832 A328833 A328834

Keyword

nonn

Author

Antti Karttunen, Oct 30 2019

Status

approved