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A139055 Sum of proper divisors of the number of partitions of n. 2
0, 1, 1, 1, 1, 1, 9, 14, 42, 54, 64, 19, 1, 105, 196, 153, 183, 191, 536, 333, 1548, 1014, 257, 1649, 1282, 4284, 3326, 2870, 1483, 7500, 4390, 4419, 7641, 9866, 7461, 1, 5435, 9097, 38511, 50214, 29913, 33874, 41283, 22041, 47954, 109338, 107806, 77175, 61579, 129998 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,7

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000 (calculated from the b-files at A000041 and A001065)

FORMULA

a(n) = A001065(A000041(n)).

EXAMPLE

a(7) = 9 because the number of partitions of 7 is 15 and the sum of proper divisors of 15 is equal to 1 + 3 + 5 = 9.

MATHEMATICA

s[n_] := DivisorSigma[1, n] - n; Array[s[PartitionsP[#]] &, 50] (* Amiram Eldar, Jan 07 2020 *)

PROG

(PARI) a(n) = my(p=numbpart(n)); sigma(p) - p; \\ Michel Marcus, Jan 07 2020

CROSSREFS

Cf. A000041, A001065, A139041.

Sequence in context: A175201 A066793 A275508 * A294030 A079625 A027009

Adjacent sequences:  A139052 A139053 A139054 * A139056 A139057 A139058

KEYWORD

nonn

AUTHOR

Omar E. Pol, Apr 16 2008

STATUS

approved

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Last modified October 24 07:04 EDT 2020. Contains 337975 sequences. (Running on oeis4.)