OFFSET
1,2
FORMULA
(7^n + 7^m) / 2, n = 0, 1, 2, 3 ..., m = 0, 1, 2, 3, ... n.
EXAMPLE
a(4) = 25 = (7^2+7^0) / 2
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Jeremy Gardiner, Jul 21 2002
STATUS
approved