A377870 a(n) = A359550(n) * A359550(A276085(n)), where A359550 is multiplicative with a(p^e) = 1 if p > e, otherwise 0, and A276085 is fully additive with a(p) = p#/p.

0, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 0, 1, 1, 0, 0, 1, 1, 1, 0, 0, 1, 1, 0, 0, 1, 0, 0, 1, 1, 1, 0, 0, 1, 0, 0, 1, 1, 0, 0, 1, 1, 1, 0, 1, 1, 1, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 0, 0, 1, 1, 0, 0, 0, 1, 0, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 0

Offset

1

Links

Antti Karttunen, Table of n, a(n) for n = 1..100000

Index entries for characteristic functions

Index entries for sequences related to primorial base

Formula

a(n) = A359550(n) * A377868(n).

Prog

(PARI)
A359550(n) = { my(f=factor(n)); for(i=1, #f~, if(f[i, 1] <= f[i, 2], return(0))); return(1); }; \\ After code in A048103
A276085(n) = { my(f = factor(n)); sum(k=1, #f~, f[k, 2]*prod(i=1, primepi(f[k, 1]-1), prime(i))); };
A377868(n) = if(isprime(n), 1, my(x=A276085(n), pp); forprime(p=2, , pp = p^p; if(!(x%pp), return(0)); if(pp > x, return(1))));
A377870(n) = (A359550(n) && A377868(n));

Crossrefs

Characteristic function of A377871.

Cf. A276085, A359550, A377868.

Sequence in context: A323153 A288861 A030190 * A353471 A157658 A296211

Adjacent sequences: A377867 A377868 A377869 * A377871 A377872 A377873

Keyword

nonn

Author

Antti Karttunen, Nov 10 2024

Status

approved