OFFSET
1,1
EXAMPLE
a(1) = 6 = 2*2*2 - 2;
a(2) = 10 = 2*2*3 - 2;
a(3) = 15 = 2*3*3 - 3;
a(4) = 18 = 2*2*5 - 2;
a(5) = 24 = 3*3*3 - 3.
CROSSREFS
KEYWORD
nonn,less
AUTHOR
Juri-Stepan Gerasimov, Jul 12 2009
EXTENSIONS
Definition reformulated, a(11), a(38) etc. corrected by R. J. Mathar, Jul 16 2009
STATUS
approved