OFFSET
1,6
COMMENTS
Divide each Jacobsthal number by its primitive part.
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..4096
PROG
(PARI)
A001045(n) = ((2^n - ((-1)^n)) / 3);
A105603(n) = if(1==n, n, (-1)^eulerphi(n)*polcyclo(n, -2)); \\ After Wolfdieter Lang's formula in that entry.
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Paul Barry, Apr 15 2005
EXTENSIONS
More terms from Antti Karttunen, Nov 01 2017
STATUS
approved