

A171916


Van Eck's sequence (cf. A181391) starting with a(1) = 6.


0



6, 0, 0, 1, 0, 2, 0, 2, 2, 1, 6, 10, 0, 6, 3, 0, 3, 2, 9, 0, 4, 0, 2, 5, 0, 3, 9, 8, 0, 4, 9, 4, 2, 10, 22, 0, 7, 0, 2, 6, 26, 0, 4, 11, 0, 3, 20, 0, 3, 3, 1, 41, 0, 5, 30, 0, 3, 7, 21, 0, 4, 18, 0, 3, 7, 7, 1, 16, 0, 6, 30, 16, 4, 12, 0, 6, 6, 1, 11, 35, 0, 6, 5, 29, 0, 4, 13, 0, 3, 25, 0
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


COMMENTS

Van Eck's sequence is defined by a(n+1) = min { k > 0  a(nk) = a(n) } or 0 if this set is empty, i.e., a(n) does not appear earlier in the sequence.  M. F. Hasler, Jun 15 2019


LINKS

Table of n, a(n) for n=1..91.


PROG

(PARI) A171916_vec(N, a=6, i=Map())={vector(N, n, a=if(n>1, iferr(nmapget(i, a), E, 0)+mapput(i, a, n), a))} \\ M. F. Hasler, Jun 15 2019


CROSSREFS

Cf. A181391, A171911, ..., A171918 (same but starting with 0, 1, ..., 8).
Sequence in context: A225339 A324878 A324398 * A325740 A222118 A267333
Adjacent sequences: A171913 A171914 A171915 * A171917 A171918 A171919


KEYWORD

nonn


AUTHOR

N. J. A. Sloane, Oct 22 2010


EXTENSIONS

Name edited and crossreferences added by M. F. Hasler, Jun 15 2019


STATUS

approved



