OFFSET
1,4
COMMENTS
LINKS
J. Bayless, The Lucas-Pratt primality tree, Math. Comp. vol 77 (2008) 495-502.
PROG
(PARI) LP(p) = my(f=factor(p-1)); if(p <= 2, 0, 1+vecsum(vector(#f~, k, LP(f[k, 1]))));
a(n) = LP(prime(n)); \\ Daniel Suteu, Nov 03 2019
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
R. J. Mathar, Jul 15 2007, Mar 07 2008
STATUS
approved