OFFSET
1,2
COMMENTS
3 is the only prime member, a(3) onwards a(n)-1 is prime.
MATHEMATICA
Join[{1, 3}, Rest[(Prime[#]+1)&/@Table[(n(n+1))/2+1, {n, 50}]]] (* Harvey P. Dale, Jul 25 2011 *)
PROG
(PARI) a(n)=if(n<3, [1, 3][n], prime(n*(n-1)/2+1)+1) \\ Charles R Greathouse IV, Jul 24 2011
CROSSREFS
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Sep 18 2002
EXTENSIONS
More terms from Sascha Kurz, Jan 30 2003
STATUS
approved