OFFSET
1,2
EXAMPLE
a(1)=1-0=1, a(2)=5-1=4, a(3)=7-4=3, a(4)=11-6=5, a(5)=13-8=5, a(6)=17-9=8.
CROSSREFS
KEYWORD
nonn
AUTHOR
Juri-Stepan Gerasimov, Dec 07 2009
STATUS
approved