

A066528


Nonpalindromic 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



