A053240 n for which values not equal to 2 occur in the expansion of A053238.

5, 20, 21, 29, 34, 49, 50, 56, 57, 65, 70, 79, 80, 94, 99, 108, 109, 123, 132, 133, 145, 146, 154, 155, 170, 171, 177, 178, 198, 200, 201, 227, 230, 231, 239, 244, 253, 254, 259, 260, 274, 277, 278, 280, 289, 290, 304, 307, 308, 310, 327, 332, 340, 341, 347

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, A053226, A053238, A053239, A053241 (complement), A053242, A053243, A053244, A053245.

Programs

Haskell

import Data.List (findIndices)
a053240 n = a053240_list !! (n-1)
a053240_list = map (+ 1) $ findIndices (/= 2) a053238_list
-- Reinhard Zumkeller, Oct 16 2011

Maple

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