A328591 Even bisection of A328590: a(n) = A328578(2n) - A257993(2n).

1, 2, 0, 2, 3, -1, 3, 2, 0, 4, 4, -1, 4, 5, -2, 2, 1, 0, 3, 4, -1, 4, 4, 0, 5, 5, -1, 5, 3, -2, 3, 2, 0, 4, 4, -1, 5, 5, 0, 5, 6, -1, 4, 6, -2, 4, 5, 0, 5, 5, -1, 5, 6, 0, 6, 3, -1, 7, 7, -2, 1, 5, 0, 6, 6, -1, 6, 5, 0, 7, 7, -1, 7, 8, -2, 2, 1, 0, 6, 7, -1, 7, 3, 0, 7, 5, -1, 3, 8, -2, 6, 2, 0, 7, 7, -1, 7, 8, 0, 8, 8, -1, 8, 9, -1

Offset: 1

Author

Antti Karttunen, Oct 21 2019

Keywords

• sign

Links

• Antti Karttunen, Table of n, a(n) for n = 1..16384
• Index entries for sequences related to primorial base

Crossrefs

Cf. A257993, A276086, A328578, A328590.

Programs

PARI

A257993(n) = { for(i=1,oo,if(n%prime(i),return(i))); }
A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
A328578(n) = A257993(A276086(A276086(n)));
A328590(n) = (A328578(n) - A257993(n));
A328591(n) = A328590(n+n);

Formula

a(n) = A328590(2n) = A328578(2n) - A257993(2n).