A053242 Numbers k such that A053238(k) = 1.

20, 21, 49, 50, 56, 57, 79, 80, 108, 109, 132, 133, 145, 146, 155, 170, 171, 177, 178, 201, 230, 231, 253, 254, 260, 277, 278, 289, 290, 307, 308, 341, 347, 348, 376, 382, 383, 405, 406, 412, 413, 424, 425, 437, 438, 467, 495, 496, 548, 549, 555, 570, 585

Offset

1,1

Links

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

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);

Prog

(Haskell)
import Data.List (elemIndices)
a053242 n = a053242_list !! (n-1)
a053242_list = map (+ 1) $ elemIndices 1 a053238_list
-- Reinhard Zumkeller, Oct 16 2011

Crossrefs

Cf. A000203, A053226, A053238, A053239, A053240, A053241, A053243, A053244, A053245 (subsequence).

Sequence in context: A041804 A041802 A041800 * A041818 A041816 A041814

Adjacent sequences: A053239 A053240 A053241 * A053243 A053244 A053245

Keyword

nonn

Author

Asher Auel, Jan 10 2000

Status

approved