A053234 Numbers n such that A053230(n) = 1.

1, 2, 31, 32, 38, 39, 67, 68, 74, 75, 98, 99, 128, 129, 157, 197, 198, 201, 228, 229, 240, 241, 247, 248, 262, 277, 278, 283, 284, 307, 308, 313, 314, 332, 333, 339, 340, 349, 369, 370, 382, 383, 386, 400, 401, 413, 414, 430, 431, 459, 460, 475, 489, 490, 502

Offset: 1

Author

Asher Auel, Jan 10 2000

Keywords

• nonn

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000203, A053224, A053230, A053231, A053232, A053233, A053235, A053236, A053237.

Programs

Haskell

import Data.List (elemIndices)
a053234 n = a053234_list !! (n-1)
a053234_list = map (+ 1) $ elemIndices 1 a053230_list
-- Reinhard Zumkeller, May 07 2012

Maple

with(numtheory): f := [seq( `if`((sigma(i+1) > sigma(i)),i,print( )), i=1..5000)];
seq( `if`(f[i+1] - f[i] = 2,i,print( )), i=1..1000);