

A317921


a(1) = a(2) = 1; for n >= 3, a(n) = 3*a(t(n))  a(nt(n)) where t = A004001.


1



1, 1, 2, 2, 5, 5, 4, 4, 13, 13, 10, 7, 7, 7, 8, 8, 35, 35, 26, 17, 8, 8, 8, 8, 11, 14, 17, 17, 17, 17, 16, 16, 97, 97, 70, 43, 16, 11, 11, 11, 11, 11, 2, 7, 16, 25, 34, 43, 43, 43, 43, 43, 43, 43, 40, 37, 34, 31, 31, 31, 31, 31, 32, 32, 275, 275, 194, 113, 32, 49, 130, 130, 130, 130, 130
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,3


COMMENTS

Sequence has a fractallike structure. Each generation (between consecutive powers of 2) provides a pattern which looks like an EKG signal since maximum value of a(n) (in corresponding generation) is damped step by step.


LINKS

Altug Alkan, Table of n, a(n) for n = 1..32768
Altug Alkan, Line plot of a(n) for n <= 2^17


PROG

(PARI) t=vector(99); t[1]=t[2]=1; for(n=3, #t, t[n] = t[nt[n1]]+t[t[n1]]); a=vector(99); a[1]=a[2]=1; for(n=3, #a, a[n] = 3*a[t[n]]a[nt[n]]); a


CROSSREFS

Cf. A004001, A317648, A317754.
Sequence in context: A239005 A236935 A213187 * A195710 A321304 A280511
Adjacent sequences: A317918 A317919 A317920 * A317922 A317923 A317924


KEYWORD

sign,look


AUTHOR

Altug Alkan, Aug 11 2018


STATUS

approved



