A045859 Numbers whose square has initial digit '5'.

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

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