The On-Line Encyclopedia of Integer Sequences (OEIS)

A328310 revision #3

A328310

a(n) = A051903(A003415(n)) - A051903(n).

-1, -1, 0, -1, 0, -1, -1, -1, 0, -1, 2, -1, 1, 2, 1, -1, -1, -1, 1, 0, 0, -1, -1, -1, 0, 0, 3, -1, 0, -1, -1, 0, 0, 1, 0, -1, 0, 3, -1, -1, 0, -1, 2, -1, 1, -1, 0, -1, 0, 1, 1, -1, 1, 3, -1, 0, 0, -1, 0, -1, 0, -1, 0, 1, 0, -1, 1, 0, 0, -1, -1, -1, 0, -1, 2, 1, 0, -1, 0, -1, 0, -1, 0, 0, 1, 4, -1, -1, -1, 1, 3, 0, 1, 2

(list; graph; refs; listen; history; text; internal format)

OFFSET

2,11

LINKS

Table of n, a(n) for n=2..95.

FORMULA

a(n) = A051903(A003415(n)) - A051903(n).

a(n) = A328311(n) - 1.

PROG

(PARI)

A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));

A051903(n) = if((1==n), 0, vecmax(factor(n)[, 2]));