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A030466 Squares that are concatenations of two consecutive nonzero numbers. 9
183184, 328329, 528529, 715716, 60996100, 1322413225, 4049540496, 106755106756, 453288453289, 20661152066116, 29752082975209, 2214532822145329, 2802768328027684, 110213248110213249, 110667555110667556, 147928995147928996, 178838403178838404, 226123528226123529 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Iain Fox, Table of n, a(n) for n = 1..1000

Pante Stanica, Squares as concatenation of consecutive integers, Slides, West Coast Number Theory, Dec 17 2017.

MATHEMATICA

fQ[n_] := IntegerQ[Sqrt[n*10^Floor[1 + Log10[n + 1]] + n + 1]]; (* Robert G. Wilson v, Dec 27 2017 *)

PROG

(PARI) lista(nn) = forstep(n=183, nn, [3, 5, 7, 5, 3, 1, 4, 7, 5, 3, 5, 7, 5, 3, 5, 7, 5, 3, 5, 7, 4, 1], my(s = eval(concat(Str(n), Str(n+1)))); if(issquare(s), print1(s, ", "))) \\ Iain Fox, Dec 27 2017

CROSSREFS

Cf. A000993, A030465, A030467, A054214, A054215, A054216, A020339, A020340.

Sequence in context: A249959 A250013 A258842 * A233956 A249232 A086478

Adjacent sequences:  A030463 A030464 A030465 * A030467 A030468 A030469

KEYWORD

nonn,base

AUTHOR

Patrick De Geest

EXTENSIONS

a(15)-a(17) from Arkadiusz Wesolowski, Apr 02 2014

a(18) from Iain Fox, Dec 27 2017

STATUS

approved

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Last modified June 21 07:27 EDT 2021. Contains 345358 sequences. (Running on oeis4.)