A171865 Positions of 0's in A181391.

1, 2, 4, 6, 11, 13, 18, 21, 25, 31, 36, 42, 45, 48, 53, 57, 60, 64, 67, 73, 82, 85, 90, 93, 99, 102, 106, 111, 117, 122, 126, 130, 135, 139, 143, 149, 153, 157, 163, 169, 174, 180, 184, 188, 197, 200, 203, 209, 213, 216, 226, 229, 233, 237, 243, 247, 252, 255, 258, 264, 270

Offset

1,2

Comments

A181391(a(n)) = 0; the sequence is infinite, proof by Jan Ritsema van Eck in comments in A181391.

Links

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

Prog

(Haskell)
import Data.List (elemIndices)
a171865 n = a171865_list !! (n-1)
a171865_list = map (+ 1) $ elemIndices 0 a181391_list
-- Reinhard Zumkeller, Oct 31 2011
(Python)
A181391_list, A171865_list = [0, 0], [1, 2]
for n in range(1, 10**4):
....for m in range(n-1, -1, -1):
........if A181391_list[m] == A181391_list[n]:
............A181391_list.append(n-m)
............break
....else:
........A181391_list.append(0)
........A171865_list.append(n+2) # Chai Wah Wu, Jan 02 2015

Crossrefs

Cf. A181391, A171868.

Sequence in context: A327309 A350668 A078198 * A372622 A344622 A068059

Adjacent sequences: A171862 A171863 A171864 * A171866 A171867 A171868

Keyword

nonn

Author

N. J. A. Sloane, Oct 17 2010

Status

approved