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 A039686 Squares which are the concatenation of two nonzero squares. 7
 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 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Intersection of A191933 and A000290; A193095(a(n))>0 and A010052(a(n))=1. [Reinhard Zumkeller, Jul 17 2011] REFERENCES D. Wells, Curious and interesting numbers, Penguin Books, p. 152. LINKS David W. Wilson, Table of n, a(n) for n = 1..1000 EXAMPLE 1225=35^2, 225=15^2, 1=1^2. MATHEMATICA 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 *) PROG (Haskell) a039686 n = a039686_list !! (n-1) a039686_list = filter ((== 1) . a010052) a191933_list -- Reinhard Zumkeller, Jul 17 2011 CROSSREFS Cf. A048375. Sequence in context: A216870 A016922 A147608 * A038628 A158638 A198386 Adjacent sequences:  A039683 A039684 A039685 * A039687 A039688 A039689 KEYWORD nonn,base,changed AUTHOR EXTENSIONS More terms from Patrick De Geest, 03/99. STATUS approved

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Last modified May 22 04:30 EDT 2013. Contains 225511 sequences.