A071326 - OEIS

A071326

Sum of squares > 1 dividing n.

0, 0, 0, 4, 0, 0, 0, 4, 9, 0, 0, 4, 0, 0, 0, 20, 0, 9, 0, 4, 0, 0, 0, 4, 25, 0, 9, 4, 0, 0, 0, 20, 0, 0, 0, 49, 0, 0, 0, 4, 0, 0, 0, 4, 9, 0, 0, 20, 49, 25, 0, 4, 0, 9, 0, 4, 0, 0, 0, 4, 0, 0, 9, 84, 0, 0, 0, 4, 0, 0, 0, 49, 0, 0, 25, 4, 0, 0, 0, 20, 90, 0, 0, 4, 0, 0, 0, 4, 0, 9, 0, 4, 0, 0, 0, 20, 0, 49, 9, 129

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OFFSET

1,4

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..16384

FORMULA

a(n) = A035316(n)-1.

Sum_{d|n, d>1} A010052(d). - Antti Karttunen, Nov 17 2017

MATHEMATICA

Array[DivisorSum[#, # &, IntegerQ@ Sqrt@ # &] - 1 &, 100] (* Michael De Vlieger, Nov 17 2017 *)

PROG

(PARI) A071326(n) = sumdiv(n, d, (d>1)*issquare(d)*d); \\ Antti Karttunen, Nov 17 2017