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A045859 Numbers whose square has initial digit '5'. 2
23, 24, 71, 72, 73, 74, 75, 76, 77, 224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 708, 709, 710, 711, 712, 713, 714, 715, 716, 717, 718, 719, 720, 721, 722, 723, 724, 725, 726, 727, 728, 729, 730 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

A000030(A000290(a(n))) = 5. [Reinhard Zumkeller, Mar 07 2010]

LINKS

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

MATHEMATICA

Rest[Table[If[First[IntegerDigits[n^2]] == 5, n, 0], {n, 1, 2500}]// Union] (* José María Grau Ribas, Feb 15 2010 *)

PROG

(PARI) isok(n) = digits(n^2)[1] == 5; \\ Michel Marcus, Dec 13 2017

CROSSREFS

Cf. A045788.

Sequence in context: A042062 A042060 A042058 * A042078 A042080 A042076

Adjacent sequences:  A045856 A045857 A045858 * A045860 A045861 A045862

KEYWORD

nonn,base

AUTHOR

Jeff Burch

STATUS

approved

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Last modified December 8 23:37 EST 2021. Contains 349596 sequences. (Running on oeis4.)