OFFSET
0,4
COMMENTS
LINKS
Michael Gilleland, Some Self-Similar Integer Sequences
Ilya Gutkovskiy, Extended graphical example
MATHEMATICA
a[0] = 0; a[1] = 1; a[n_] := If[EvenQ[n], DivisorSigma[1, a[n/2]], DivisorSigma[1, a[(n - 1)/2] + a[(n + 1)/2]]]; Table[a[n], {n, 0, 100}]
PROG
(PARI) a(n) = if(n<2, n, if(Mod(n, 2), sigma(a((n - 1)/2) + a((n + 1)/2)), sigma(a(n/2))));
for(n=0, 100, print1(a(n), ", ")) \\ Indranil Ghosh, Mar 16 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Mar 16 2017
STATUS
approved