A045857 Numbers whose square has initial digit '3'.

6, 18, 19, 55, 56, 57, 58, 59, 60, 61, 62, 63, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199, 548, 549, 550, 551, 552, 553, 554, 555, 556, 557, 558, 559, 560, 561, 562, 563

Offset: 1

Author

Jeff Burch

Keywords

• nonn
• base

Links

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

Crossrefs

Cf. A045786.

Programs

Mathematica

Select[Range[600],IntegerDigits[#^2][[1]]==3&] (* Harvey P. Dale, Jan 09 2020 *)

PARI

isok(n) = digits(n^2)[1] == 3; \\ Michel Marcus, May 28 2017