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A045856 Numbers whose square has initial digit '2'. 2
5, 15, 16, 17, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 448, 449, 450, 451, 452, 453, 454, 455, 456 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Seiichi Manyama, Table of n, a(n) for n = 1..10000

PROG

(PARI) isok(n) = digits(n^2)[1] == 2; \\ Michel Marcus, May 28 2017

CROSSREFS

Cf. A045785

Sequence in context: A184288 A015666 A291627 * A102185 A030486 A101238

Adjacent sequences:  A045853 A045854 A045855 * A045857 A045858 A045859

KEYWORD

nonn,base

AUTHOR

Jeff Burch

EXTENSIONS

Corrected by Seiichi Manyama, May 28 2017

STATUS

approved

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Last modified December 6 10:24 EST 2021. Contains 349563 sequences. (Running on oeis4.)