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A039686
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Squares which are the concatenation of two nonzero squares.
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7
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49, 169, 361, 1225, 1444, 1681, 3249, 4225, 4900, 15625, 16900, 36100, 42025, 49729, 64009, 81225, 93025, 122500, 144400, 168100, 225625, 237169, 324900, 422500, 490000, 519841, 819025, 950625, 970225, 1024144, 1442401, 1562500
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OFFSET
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1,1
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COMMENTS
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Intersection of A191933 and A000290; A193095(a(n))>0 and A010052(a(n))=1. [Reinhard Zumkeller, Jul 17 2011]
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REFERENCES
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D. Wells, Curious and interesting numbers, Penguin Books, p. 152.
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LINKS
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David W. Wilson, Table of n, a(n) for n = 1..1000
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EXAMPLE
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1225=35^2, 225=15^2, 1=1^2.
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MATHEMATICA
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t = Table[n^2, {n, 750}]; f[j_, k_] := Block[{n = j*10^Floor[1 + Log10@ k] + k}, If[IntegerQ@ Sqrt@ n, n, 0]]; Take[ Union@ Flatten@ Table[ f[t[[j]], t[[k]]], {j, 250}, {k, 750}], {2, 33}] (* Robert G. Wilson v, July 18 2011 *)
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PROG
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(Haskell)
a039686 n = a039686_list !! (n-1)
a039686_list = filter ((== 1) . a010052) a191933_list
-- Reinhard Zumkeller, Jul 17 2011
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CROSSREFS
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Cf. A048375.
Sequence in context: A216870 A016922 A147608 * A038628 A158638 A198386
Adjacent sequences: A039683 A039684 A039685 * A039687 A039688 A039689
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KEYWORD
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nonn,base,changed
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AUTHOR
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Felice Russo
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EXTENSIONS
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More terms from Patrick De Geest, 03/99.
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STATUS
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approved
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