A279428 Numbers k such that k^2 has an odd number of digits and the middle digit is 8.

17, 22, 28, 104, 109, 122, 126, 141, 151, 164, 167, 184, 192, 197, 202, 207, 221, 232, 268, 279, 293, 298, 303, 308, 316, 1004, 1009, 1014, 1019, 1024, 1029, 1048, 1053, 1067, 1081, 1090, 1104, 1113, 1122, 1135, 1144, 1157, 1170, 1174, 1187, 1191, 1195, 1212

Offset

1,1

Links

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

Example

17^2 = 2(8)9, 164^2 = 26(8)96, 1024^2 = 104(8)576.

Mathematica

ond8Q[n_]:=Module[{n2=IntegerDigits[n^2], len}, len=Length[n2]; OddQ[len]&&n2[[(len+1)/2]] == 8]; Select[Range[1500], ond8Q] (* Harvey P. Dale, Sep 25 2023 *)

Crossrefs

Cf. A279420-A279427, A279429.

Sequence in context: A054478 A136198 A158246 * A275244 A002252 A064543

Adjacent sequences: A279425 A279426 A279427 * A279429 A279430 A279431

Keyword

nonn,base,easy

Author

Lars Blomberg, Dec 22 2016

Status

approved