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A275769 Least k such that n divides sigma(k!) (k > 0). 1
1, 3, 2, 3, 4, 3, 10, 5, 5, 4, 9, 3, 6, 10, 4, 7, 8, 5, 14, 4, 11, 9, 12, 5, 21, 6, 14, 10, 42, 4, 6, 11, 9, 8, 14, 5, 36, 14, 6, 5, 22, 11, 35, 9, 5, 12, 24, 7, 13, 21, 8, 7, 69, 14, 9, 10, 14, 42, 60, 4, 21, 6, 14, 12, 8, 9, 45, 8, 12, 14, 20, 5, 10, 36, 21, 14, 10, 6, 40, 8, 14, 22, 81, 11 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Chai Wah Wu, Table of n, a(n) for n = 1..10000

EXAMPLE

a(5) = 4 because sigma(4!) = 60 is divisible by 5.

MATHEMATICA

Table[k = 1; While[! Divisible[DivisorSigma[1, k!], n], k++]; k, {n, 84}] (* Michael De Vlieger, Aug 08 2016 *)

PROG

(PARI) a(n) = {my(k=1); while(sigma(k!) % n != 0, k++); k; }

CROSSREFS

Cf. A000203, A062569.

Sequence in context: A147658 A221529 A105161 * A094365 A272886 A098822

Adjacent sequences:  A275766 A275767 A275768 * A275770 A275771 A275772

KEYWORD

nonn

AUTHOR

Altug Alkan, Aug 08 2016

STATUS

approved

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Last modified April 4 05:34 EDT 2020. Contains 333212 sequences. (Running on oeis4.)