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 A034291 Triangular numbers that have some nontrivial permutation of digits which is also triangular. 1
 120, 153, 210, 253, 325, 351, 496, 946, 1378, 1485, 1830, 1891, 2145, 2415, 2701, 3081, 3570, 3655, 3741, 3916, 4095, 4371, 4560, 4851, 4950, 5356, 5460, 5565, 5778, 6555, 7021, 7381, 7503, 7875, 8911, 9045, 9316, 10296, 11325, 11476, 11935, 12090 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Table of n, a(n) for n=1..42. MATHEMATICA tnpQ[n_]:=Module[{p=FromDigits/@Rest[Permutations[IntegerDigits[n]]], q}, q= DeleteCases[ p, _?(IntegerLength[#]!=IntegerLength[n]&)]; Count[q, _?(OddQ[ Sqrt[8#+1]]&)]>0]; Select[Accumulate[Range[200]], tnpQ] CROSSREFS Cf. A000217. Sequence in context: A248662 A259826 A192277 * A039602 A316835 A179642 Adjacent sequences: A034288 A034289 A034290 * A034292 A034293 A034294 KEYWORD nonn,base AUTHOR Erich Friedman EXTENSIONS Offset set to 1 by Sean A. Irvine, Aug 20 2020 STATUS approved

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Last modified March 4 11:14 EST 2024. Contains 370528 sequences. (Running on oeis4.)