OFFSET
1,1
FORMULA
Conjecture: a(n)= +2*a(n-7) -a(n-14).
EXAMPLE
n^2+7*a(n) = smallest square:
1^2+7*5=6^2
2^2+7*3=5^2
3^2+7*1=4^2
4^2+7*12=10^2.
MATHEMATICA
Reap[Do[Do[If[IntegerQ[Sqrt[n^2+7m]], Sow[m]; Break[]], {m, 10000}], {n, 200}]][[2, 1]]
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov, Dec 05 2010
STATUS
approved