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A086293 Sum of divisors of 7-smooth numbers. 4
1, 3, 4, 7, 6, 12, 8, 15, 13, 18, 28, 24, 24, 31, 39, 42, 32, 60, 31, 40, 56, 72, 63, 48, 91, 90, 96, 78, 124, 57, 93, 120, 120, 168, 104, 127, 144, 195, 124, 186, 121, 224, 234, 252, 171, 217, 192, 280, 248, 360, 156, 312, 255, 240, 336, 403, 228, 372, 378 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000

FORMULA

a(n) = A000203(A002473(n)).

MATHEMATICA

DivisorSigma[1, Select[Range[500], Max[Transpose[FactorInteger[#]][[1]]] <= 7 &]] (* Amiram Eldar, Jan 06 2020 after G. C. Greubel at A086288 *)

CROSSREFS

Cf. A000203, A002473, A086292.

Sequence in context: A003979 A084250 A090128 * A337708 A348944 A003981

Adjacent sequences:  A086290 A086291 A086292 * A086294 A086295 A086296

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Jul 15 2003

STATUS

approved

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Last modified May 17 17:06 EDT 2022. Contains 353747 sequences. (Running on oeis4.)