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A356445
a(n) is the number of times that A064440(n) occurs as the sum of proper divisors function (A001065).
2
2, 3, 5, 7, 13, 17, 19, 23, 31, 41, 59, 61, 67, 79, 83, 97, 101, 109, 113, 127, 131, 139, 149, 151, 193, 199, 223, 227, 229, 277, 283, 317, 397, 433, 521, 541, 577, 607, 677, 743, 757, 811, 863, 881, 911, 971, 1031, 1049, 1063, 1093, 1249, 1319, 1373, 1433, 1489
OFFSET
1,1
COMMENTS
The record values correspond to the terms of A064440.
All the terms are primes by definition.
LINKS
FORMULA
a(n) = A048138(A064440(n)).
MATHEMATICA
seq[max_] := Module[{s = Table[0, {n, 1, max}], i, v = {}, m = 0}, Do[If[(i = DivisorSigma[1, n] - n) <= max, s[[i]]++], {n, 2, (max - 1)^2}]; Do[If[s[[i]] > m && PrimeQ[s[[i]]], m = s[[i]]; AppendTo[v, s[[i]]]], {i, 1, max}]; v]; seq[2000]
CROSSREFS
KEYWORD
nonn
AUTHOR
Amiram Eldar, Sep 23 2022
STATUS
approved