A185031 Numbers n (other than powers of 2) such that the absolute value of abundance(n) is a square.

5, 6, 12, 14, 17, 28, 37, 38, 44, 70, 88, 92, 98, 101, 108, 110, 134, 152, 168, 170, 172, 197, 206, 220, 248, 257, 284, 348, 374, 398, 401, 410, 428, 434, 496, 550, 577, 580, 590, 604, 632, 638, 677, 726, 748, 752, 798, 884, 910, 918, 952, 974, 988, 1032

Offset

1,1

Links

Arkadiusz Wesolowski, Table of n, a(n) for n = 1..10000

Eric Weisstein's World of Mathematics, Abundance

Mathematica

lst = {}; e = 10; Do[If[IntegerQ[Abs[DivisorSigma[1, n] - 2*n]^(1/2)], AppendTo[lst, n]], {n, 2^e + e}]; Complement[lst, Table[Power[2, m], {m, 0, e}]]

Crossrefs

Supersequence of A188484.

Sequence in context: A285404 A047319 A244368 * A138925 A088767 A032707

Adjacent sequences: A185028 A185029 A185030 * A185032 A185033 A185034

Keyword

nonn

Author

Arkadiusz Wesolowski, Jan 23 2012

Status

approved