A331734 a(n) = A033879(A225546(n)).

1, 1, 1, 2, 1, 1, 1, 0, 5, 1, 1, -4, 1, 1, 1, 4, 1, -3, 1, -28, 1, 1, 1, -12, 41, 1, -19, -508, 1, 1, 1, 2, 1, 1, 1, 14, 1, 1, 1, -60, 1, 1, 1, -131068, -115, 1, 1, -2, 3281, -39, 1, -8589934588, 1, -51, 1, -1020, 1, 1, 1, -124, 1, 1, -2035, 6, 1, 1, 1, -36893488147419103228, 1, 1, 1, -12, 1, 1, -199, -680564733841876926926749214863536422908

Offset

1,4

Links

Antti Karttunen, Table of n, a(n) for n = 1..136

Formula

a(n) = A033879(A225546(n)) = 2*A225546(n) - A331733(n).

For all n, a(A005117(n)) = 1. [It is not known if there are 1's in any other positions. See Jianing Song's Oct 13 2019 comment in A033879.]

For a necessary condition that a(s) would be zero for any square, see A331741.

Prog

(PARI)
A048675(n) = { my(f = factor(n)); sum(k=1, #f~, f[k, 2]*2^primepi(f[k, 1]))/2; };
A331734(n) = if(issquarefree(n), 1, my(f=factor(n), u=#binary(vecmax(f[, 2])), prods=vector(u, x, 1), m=1, e); for(i=1, u, for(k=1, #f~, if(bitand(f[k, 2], m), prods[i] *= f[k, 1])); m<<=1); (2*prod(i=1, u, prime(i)^A048675(prods[i]))) - prod(i=1, u, (prime(i)^(1+A048675(prods[i]))-1)/(prime(i)-1)));

Crossrefs

Cf. A005117, A033879, A225546, A331733, A331735, A331741.

Cf. A323244, A323174, A324055, A324185, A324546 for other permutations of the deficiency, and also A324574, A324654.

Sequence in context: A126310 A109086 A213620 * A105794 A345008 A316866

Adjacent sequences: A331731 A331732 A331733 * A331735 A331736 A331737

Keyword

sign

Author

Antti Karttunen, Feb 02 2020

Status

approved