login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A272601
Composites n such that p-1 does not divide n-1 for at least one prime divisor of n-1.
2
4, 6, 8, 10, 12, 14, 15, 16, 18, 20, 22, 24, 26, 27, 28, 30, 32, 34, 35, 36, 38, 39, 40, 42, 44, 45, 46, 48, 50, 51, 52, 54, 56, 57, 58, 60, 62, 63, 64, 66, 68, 69, 70, 72, 74, 75, 76, 77, 78, 80, 82, 84, 86, 87, 88, 90, 91, 92, 93, 94, 95, 96, 98, 99, 100, 102, 104, 105, 106, 108, 110, 111, 112, 114, 115, 116
OFFSET
1,1
COMMENTS
Composites not in A272600.
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
PROG
(PARI) forcomposite(n=4, 10^3, my(q=1, f=factor(n-1)[, 1]); for(j=1, #f, if((n-1)%(f[j]-1), q=0; break)); if(!q, print1(n, ", ")));
CROSSREFS
Sequence in context: A379722 A360694 A090334 * A322368 A078941 A078942
KEYWORD
nonn
AUTHOR
Joerg Arndt, May 16 2016
STATUS
approved