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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
OFFSET
1,2
LINKS
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
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Jul 15 2003
STATUS
approved