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A198035
Numbers n such that n^2 is a concatenation of two nonzero squares with no trailing zeros in n.
1
7, 13, 19, 35, 38, 41, 57, 65, 125, 205, 223, 253, 285, 305, 475, 487, 721, 905, 975, 985, 1012, 1201, 1265, 1301, 1442, 1518, 1771, 2024, 2163, 2225, 2277, 2402, 2435, 3075, 3125, 3925, 4901, 6013, 7045, 7969, 8225, 8855, 9607, 9625, 9805, 10815, 11125, 11385, 12025
OFFSET
1,1
COMMENTS
Primitive solutions of A048375 (whose numbers can have trailing zeros).
EXAMPLE
a(150)=1002445 and 1002445^2=1004895978025=100489_5978025, x^2=317^2=100489, y^2=2445^2=5978025.
MATHEMATICA
Reap[Do[r=0; If[Mod[n, 10]>0, Do[mo=PowerMod[n, 2, 10^k]; If[mo>10^(k-1)-1 && IntegerQ[Sqrt[mo]] && IntegerQ[Sqrt[qu=Quotient[n^2, 10^k]]], r=1; Break[]], {k, Log[10, n^2]}]; If[r>0, Sow[n]; Print[{n, Sqrt[qu], Sqrt@mo}]]], {n, 7, 10^6}]][[2, 1]] (* Zak Seidov, Oct 20 2011 *)
CROSSREFS
Cf. A048375.
Sequence in context: A265629 A283191 A048375 * A208720 A208776 A108295
KEYWORD
nonn,base
AUTHOR
Zak Seidov, Oct 20 2011
STATUS
approved