OFFSET
1,1
EXAMPLE
a(1)=5 because 5=6*1-1=(6*1-1)*(6*0+1); a(2)=35 because 35=6*6-1=(6*1-1)*(6*1+1); a(3)=11 because 11=6*2-1=(6*2-1)*(6*0+1).
CROSSREFS
KEYWORD
nonn
AUTHOR
Juri-Stepan Gerasimov, Mar 09 2010
STATUS
approved