A279429 Numbers k such that k^2 has an odd number of digits and the middle digit is 9.

3, 14, 114, 118, 130, 134, 148, 158, 161, 170, 173, 176, 187, 212, 219, 228, 230, 270, 272, 281, 288, 313, 1034, 1039, 1044, 1058, 1063, 1072, 1077, 1086, 1095, 1109, 1118, 1131, 1140, 1153, 1166, 1183, 1204, 1208, 1292, 1296, 1315, 1319, 1334, 1345, 1349

Offset

1,1

Links

Lars Blomberg, Table of n, a(n) for n = 1..10000

Example

3^2 = (9), 170^2 = 28(9)00, 1086^2 = 117(9)396.

Mathematica

Select[Range[1349], OddQ[len=Length[IntegerDigits[#^2]]]&&Part[IntegerDigits[#^2], (len+1)/2]==9 &] (* Stefano Spezia, Oct 03 2023 *)

Crossrefs

Cf. A279420-A279428.

Sequence in context: A276751 A085244 A265001 * A333797 A229113 A180435

Adjacent sequences: A279426 A279427 A279428 * A279430 A279431 A279432

Keyword

nonn,base,easy

Author

Lars Blomberg, Dec 22 2016

Status

approved