A051423 Numbers k such that the sum of prime divisors of k is congruent to 2^k (mod k).

15, 77, 99, 240, 354, 18870, 284481, 302174, 433197, 440973, 453086, 2446619, 5776855, 9961111, 17986255, 19091527, 28997648, 37443680, 40074848, 47602448, 67166528, 129389763, 141963648, 146259296, 152062688, 202038871, 203444576

Offset

1,1

Comments

Prime factors counted with multiplicity. - Harvey P. Dale, Jul 25 2013

Links

Giovanni Resta, Table of n, a(n) for n = 1..88 (terms < 10^11)

Example

15 = 3*5 and 2^15 = 3+5 (mod 15).

Mathematica

Select[Range[2500000], Total[Flatten[Table[#[[1]], {#[[2]]}]&/@ FactorInteger [#]]] ==PowerMod[2, #, #]&] (* Harvey P. Dale, Jul 25 2013 *)

Crossrefs

Sequence in context: A041430 A156941 A205440 * A205609 A257925 A205433

Adjacent sequences: A051420 A051421 A051422 * A051424 A051425 A051426

Keyword

nonn,easy,nice

Author

Joe K. Crump (joecr(AT)carolina.rr.com)

Status

approved