A187711 Integers k which equal (product of divisors of k) mod (sum of divisors of k).

2, 3, 5, 7, 10, 11, 13, 17, 19, 20, 23, 29, 31, 33, 37, 40, 41, 43, 47, 53, 59, 61, 67, 71, 73, 76, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 136, 137, 139, 145, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 207, 211, 223, 227, 229, 233, 239, 241, 251, 257, 261, 263, 269, 271, 277

Offset

1,1

Links

G. C. Greubel, Table of n, a(n) for n = 1..10000

Formula

{ k : k = A187680(k) }.

Maple

isA187711 := proc(n) is(A187680(n) = n) end proc:
for n from 2 to 300 do if isA187711(n) then printf("%d, ", n) ; end if; end do: # R. J. Mathar, Mar 17 2011

Mathematica

Select[Range[300], Mod[#^(DivisorSigma[0, #]/2), DivisorSigma[1, #]] == # &] (* G. C. Greubel, Nov 05 2018 *)

Crossrefs

Cf. A000203, A007955, A187680.

Sequence in context: A048461 A338174 A058590 * A064627 A324813 A235050

Adjacent sequences: A187708 A187709 A187710 * A187712 A187713 A187714

Keyword

nonn

Author

Juri-Stepan Gerasimov, Mar 17 2011

Status

approved