OFFSET
1,1
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000 (calculated using data from Claude Goutier)
EXAMPLE
3240392401 = 29*37*41*73*1009, A001414(3240392401)=1189 = 29*41.
PROG
(PARI) sopfr(f) = f[, 1]~*f[, 2];
isCarmichael(n, f)= bittest(n, 0) && !for(i=1, #f~, (f[i, 2]==1 && n%(f[i, 1]-1)==1)||return) && (#f~>1);
isok(n) = my(f=factor(n)); isCarmichael(n, f) && !(n % sopfr(f)); \\ Michel Marcus, Jul 07 2019
CROSSREFS
KEYWORD
nonn
AUTHOR
David James Sycamore, Jul 05 2019
STATUS
approved