OFFSET
1,1
COMMENTS
The subsequence of squarefree terms gives the Carmichael numbers (A002997); cf. Korselt's criterion. - Joerg Arndt, May 17 2016
LINKS
Donovan Johnson, Table of n, a(n) for n = 1..10000
Wikipedia, Korselt's criterion
MATHEMATICA
Select[ Range[2, 10^4], !PrimeQ[ # ] && Union[ Mod[ # - 1, Transpose[ FactorInteger[ # ]][[1]] - 1]] == {0} &]
PROG
(PARI) is080062(n)=if(isprime(n), return(0)); my(f=factor(n)[, 1]); for(j=1, #f, if((n-1)%(f[j]-1), return(0))); 1; \\ Joerg Arndt, May 17 2016
CROSSREFS
KEYWORD
nonn
AUTHOR
Robert G. Wilson v, Jan 23 2003
STATUS
approved