A156099 Smallest number m such that prime(n) is a factor of both m and sigma(m).

6, 6, 40, 28, 473, 117, 1139, 703, 3151, 5017, 496, 2701, 6683, 11051, 13207, 11183, 20827, 10309, 26867, 20093, 18688, 12403, 27473, 91136, 18721, 101909, 63551, 68587, 71177, 76501, 8128, 68513, 74939, 38503, 221861, 273461, 49141, 159251

Offset

1,1

Links

Donovan Johnson, Table of n, a(n) for n=1..5000

Example

a(20) = 20093. prime(20) = 71. 20093/71 = 283. sigma(20093)/71 = 288.

Mathematica

snm[p_]:=Module[{m=1}, While[!Divisible[m, p]||!Divisible[ DivisorSigma[ 1, m], p], m++]; m]; snm/@Prime[Range[40]] (* Harvey P. Dale, Dec 17 2022 *)

Crossrefs

Cf. A000040, A000203.

Sequence in context: A244957 A186982 A196075 * A278435 A279333 A278734

Adjacent sequences: A156096 A156097 A156098 * A156100 A156101 A156102

Keyword

nonn

Author

Donovan Johnson, Feb 04 2009

Status

approved