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A067225 Numbers n such that n is a square and remains a square when its leading digit is increased by one. 0
576, 2025, 11025, 57600, 202500, 342225, 950625, 1102500, 3515625, 5760000, 9272025, 11390625, 20250000, 34222500, 95062500, 110250000, 196700625, 351562500, 576000000, 927202500, 1139062500, 2025000000, 3422250000 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

EXAMPLE

576 = 24^2 and 676 = 26^2, so 576 is a term of the sequence.

MAPLE

for n from 1 to 10^6 do if issqr(n^2+10^(length(n^2)-1)) then printf(`%d, `, n^2); fi:od:

MATHEMATICA

f[n_] := Block[{a = IntegerDigits[n]}, a[[1]] = a[[1]] + 1; FromDigits[a]]; Select[ Range[10^5], IntegerQ[ Sqrt[ f[ #^2]]] & ]^2

CROSSREFS

Sequence in context: A137484 A189990 A064254 * A036514 A188787 A168660

Adjacent sequences:  A067222 A067223 A067224 * A067226 A067227 A067228

KEYWORD

base,nonn

AUTHOR

Joseph L. Pe (joseph_l_pe(AT)hotmail.com), Feb 20 2002

EXTENSIONS

Edited and extended by Robert G. Wilson v (rgwv(AT)rgwv.com), Feb 21 2002

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Last modified February 17 23:08 EST 2012. Contains 206085 sequences.