A279426 Numbers k such that k^2 has an odd number of digits and the middle digit is 6.

13, 19, 31, 103, 108, 117, 121, 125, 129, 133, 140, 147, 157, 160, 175, 178, 194, 199, 204, 209, 216, 225, 236, 238, 240, 260, 262, 264, 275, 284, 291, 296, 301, 306, 1003, 1008, 1013, 1018, 1023, 1028, 1047, 1052, 1066, 1080, 1094, 1103, 1112, 1121, 1130

Offset

1,1

Links

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

Example

13^2 = 1(6)9, 133^2 = 17(6)89, 284^2 = 80(6)56.

Mathematica

Select[Range[1200], OddQ[IntegerLength[#^2]]&&IntegerDigits[#^2][[(IntegerLength[ #^2]+1)/2]] == 6&] (* Harvey P. Dale, May 28 2023 *)

Crossrefs

Cf. A279420-A279425, A279427-A279429.

Sequence in context: A051644 A101408 A023252 * A241120 A128342 A154076

Adjacent sequences: A279423 A279424 A279425 * A279427 A279428 A279429

Keyword

nonn,base,easy

Author

Lars Blomberg, Dec 22 2016

Status

approved