OFFSET
1,1
COMMENTS
Note that k <= n^2-1, with equality occurring only if n and n+1 are a prime and a power of 2 (in either order); that is, when n is a Mersenne prime or n+1 is a Fermat prime. - T. D. Noe, Apr 08 2011
LINKS
Zak Seidov, Table of n, a(n) for n = 1..10000
MATHEMATICA
Clear[k]; Join[{2}, Table[Reduce[k*(k+1) == 0, k, Modulus -> n*(n+1)][[3, 2]], {n, 2, 100}]] (* T. D. Noe, Apr 08 2011 *)
PROG
(PARI) for(s=1, 1000, s1=s*(s+1); n=s+1; while(n*(n+1)%s1>0, n++); print1(n, ", "); ) \\ Zak Seidov, Apr 08 2011
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Benoit Cloitre, May 01 2002
STATUS
approved