A054001 Differences between numbers k such that k and k+1 have the same sum of divisors.

192, 751, 377, 30, 270, 1051, 289, 1390, 10477, 4032, 485, 787, 4812, 9041, 2568, 6252, 13746, 8101, 10253, 4908, 7, 4301, 8551, 16529, 2292, 5431, 5136, 16164, 9217, 13547, 1601, 4332, 7783, 16056, 3120, 7704, 28793, 44143, 14921, 58284

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..10134 (calculated using the b-file at A002961)

Formula

a(n) = A002961(n+1) - A002961(n).

Mathematica

Differences[Select[Range[500000], DivisorSigma[1, #]== DivisorSigma[ 1, #+1]&]] (* Harvey P. Dale, Oct 16 2011 *)
Differences[SequencePosition[DivisorSigma[1, Range[350000]], {x_, x_}][[All, 1]]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Jun 03 2021 *)

Crossrefs

Cf. A000203, A002961.

Sequence in context: A251083 A336944 A194647 * A051527 A305073 A101451

Adjacent sequences: A053998 A053999 A054000 * A054002 A054003 A054004

Keyword

nonn

Author

Asher Auel, Jan 12 2000

Extensions

More terms from David Wasserman, Mar 01 2002

Status

approved