A053235 Numbers n such that A053230(n) = 3.

158, 202, 263, 350, 387, 476, 567, 582, 701, 790, 879, 894, 926, 999, 1103, 1236, 1282, 1403, 1418, 1501, 1523, 1646, 1661, 1737, 1831, 1847, 1953, 2059, 2074, 2149, 2185, 2237, 2265, 2370, 2505, 2563, 2683, 2729, 2873, 2894, 2909, 3032, 3107, 3127

Offset

1,1

Links

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

Maple

with(numtheory): f := [seq( `if`((sigma(i+1) > sigma(i)), i, print( )), i=1..5000)];
seq( `if`(f[i+1] - f[i] = 3, i, print( )), i=1..1000);

Mathematica

Position[Differences@ Select[Range[10^4], Less @@ DivisorSigma[1, # + {0, 1}] &], 3][[All, 1]] (* Michael De Vlieger, Nov 19 2019 *)

Prog

(Haskell)
import Data.List (elemIndices)
a053235 n = a053235_list !! (n-1)
a053235_list = map (+ 1) $ elemIndices 3 a053230_list
-- Reinhard Zumkeller, May 07 2012

Crossrefs

Cf. A000203, A053224, A053230, A053231, A053232, A053233, A053234, A053236, A053237.

Sequence in context: A048930 A130864 A045245 * A352349 A255351 A088728

Adjacent sequences: A053232 A053233 A053234 * A053236 A053237 A053238

Keyword

nonn

Author

Asher Auel, Jan 10 2000

Status

approved