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 A279421 Numbers k such that k^2 has an odd number of digits and the middle digit is 1. 3
 1, 110, 119, 123, 127, 131, 142, 152, 182, 190, 210, 224, 237, 239, 261, 263, 276, 290, 310, 1035, 1040, 1059, 1073, 1087, 1096, 1105, 1123, 1132, 1141, 1145, 1154, 1167, 1171, 1184, 1188, 1209, 1213, 1217, 1285, 1289, 1293, 1312, 1316, 1331, 1346, 1357, 1368 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Lars Blomberg, Table of n, a(n) for n = 1..10000 EXAMPLE 1^2 = (1), 190^2 = 36(1)00, 1145^2 = 131(1)025. MATHEMATICA ond1Q[n_]:=Module[{len=IntegerLength[n^2]}, OddQ[len]&&IntegerDigits[n^2][[(len+1)/2]]==1]; Select[Range[1500], ond1Q] (* Harvey P. Dale, Jun 06 2018 *) CROSSREFS Cf. A279420, A279422-A279429. Sequence in context: A267254 A036230 A171236 * A135642 A166323 A194429 Adjacent sequences: A279418 A279419 A279420 * A279422 A279423 A279424 KEYWORD nonn,base,easy AUTHOR Lars Blomberg, Dec 22 2016 STATUS approved

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Last modified May 25 10:09 EDT 2024. Contains 372786 sequences. (Running on oeis4.)