OFFSET
0,2
LINKS
Donovan Johnson, Table of n, a(n) for n = 0..51
EXAMPLE
a(3)=28 because 28 is a triangular number with 3 prime factors: 28 = 2*2*7.
PROG
(PARI) a(n)=if(n<0, 0, s=1; while(abs(bigomega(s*(s+1)/2)-n)>0, s++); s*(s+1)/2)
CROSSREFS
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Sep 13 2002
EXTENSIONS
More terms from Benoit Cloitre, Sep 17 2002
a(21)-a(24) from Mohammed Bouayoun (bouyao(AT)wanadoo.fr), Mar 15 2004
Edited by Ray Chandler, Dec 17 2004
a(25) from Ray Chandler, Dec 22 2004
STATUS
approved