A269969 Index of first occurrence of -n in A269783.

0, 5, 16, 20, 42, 47, 51, 88, 97, 102, 106, 164, 175, 182, 187, 191, 274, 289, 300, 307, 312, 316, 428, 447, 460, 469, 476, 481, 485, 632, 657, 672, 685, 694, 701, 706, 710, 894, 923, 944, 959, 970, 979, 986, 991, 995, 1222, 1257, 1282, 1299, 1314, 1325, 1334

Offset

0,2

Comments

Sequence A269783 is defined by A269783(0)=0 and A269783(n+1) = A269783(n) + (-1)^(k+e)*floor(k/2), where k = #{ j<=n | A269783(j)=A269783(n) } and e=1 for A269783(n)>0, else e=0. That is, the 1st, 2nd, 3rd, 4th... occurrence of any positive integer n is followed by n resp. n-1 resp. n+1 resp. n-2, etc., and for zero or negative integers the same with opposite sign.

Links

Rémy Sigrist, Table of n, a(n) for n = 0..10000

Rémy Sigrist, PARI program

Prog

(PARI) See Links section.

Crossrefs

Cf. A269783 (main sequence), A269967 (indices of zeros), A269968 (index of first occurrence of n).

Sequence in context: A195958 A151980 A063612 * A057281 A204920 A168469

Adjacent sequences: A269966 A269967 A269968 * A269970 A269971 A269972

Keyword

nonn

Author

M. F. Hasler, Mar 08 2016

Extensions

More terms from Rémy Sigrist, May 21 2023

Status

approved