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A066528 Non-palindromic triangular numbers whose reverse is a triangular number with the same number of digits. 5
153, 351, 17578, 87571, 185745, 547581, 1461195, 5911641, 12145056, 12517506, 60571521, 65054121, 304119453, 354911403, 1775275491, 1945725771, 10246462281, 17990863516, 18226464201, 35615002605, 50620051653, 61536809971, 1222080857271, 1664224065406 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Giovanni Resta, Table of n, a(n) for n = 1..64 (terms < 2*10^24)

EXAMPLE

153 and 351 are both triangular.

MATHEMATICA

dtn[L_] := Fold[10#1+#2&, 0, L]; tritest[n_] := Module[{t}, t=Floor[N[Sqrt[2n]]]; 2n==t(t+1)]; A={}; For[i=1, i>0, i++, t=i(i+1)/2; If[tritest[tt=dtn[Reverse[IntegerDigits[t]]]]&&Mod[t, 10]>0&&t=!=tt, AppendTo[A, t]; Print[A]]]

CROSSREFS

See A069673 for another version.

Cf. A066703, A179889.

Sequence in context: A253023 A194660 A159294 * A046197 A271730 A056733

Adjacent sequences:  A066525 A066526 A066527 * A066529 A066530 A066531

KEYWORD

base,nonn

AUTHOR

Erich Friedman, Jan 08 2002

EXTENSIONS

a(22)-a(24) from Giovanni Resta, Jun 20 2015

STATUS

approved

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Last modified December 5 10:45 EST 2019. Contains 329751 sequences. (Running on oeis4.)