A369748 a(n) = Sum_{p|n, p prime} prime(n/p).
0, 2, 2, 3, 2, 8, 2, 7, 5, 14, 2, 20, 2, 20, 16, 19, 2, 36, 2, 36, 22, 34, 2, 56, 11, 44, 23, 50, 2, 89, 2, 53, 36, 62, 28, 98, 2, 70, 46, 90, 2, 129, 2, 86, 70, 86, 2, 142, 17, 126, 64, 108, 2, 164, 42, 126, 72, 112, 2, 221, 2, 130, 96, 131, 52, 229, 2, 146, 88, 221
Offset: 1
Links
- Antti Karttunen, Table of n, a(n) for n = 1..20000
Programs
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Mathematica
Table[DivisorSum[n, Prime[n/#] &, PrimeQ[#] &], {n, 100}] -
PARI
A369748(n) = if(1==n, 0, my(f=factor(n)); sum(i=1, #f~, prime(n/f[i, 1]))); \\ Antti Karttunen, Jan 22 2025