OFFSET
1,1
COMMENTS
Most first differences are alternatively 14 and 36.
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
EXAMPLE
{7,707,7007,7043,7057,22143,22157}^2={49,499849,49098049,49603849,49801249,490312449,490932649}.
MATHEMATICA
s7={}; Do[If[Take[IntegerDigits[n^2], 2]=={4, 9}&&PowerMod[n, 2, 100]==49, AppendTo[s7, n]], {n, 7, 300000}]; s7
se49Q[n_]:=Module[{id=IntegerDigits[n^2]}, Take[id, 2]==Take[id, -2] == {4, 9}]; Select[Range[5, 71000], se49Q] (* Harvey P. Dale, Apr 22 2016 *)
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Zak Seidov, Apr 22 2009
STATUS
approved