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A066702 Square numbers whose reverse is triangular with the same number of digits. 3

%I #20 Apr 13 2019 22:12:57

%S 0,1,1306449,1044000721,12957041241,1019072079081,1174279984164,

%T 6454272356676,65036563475625,67624587155889,123826990849454025,

%U 170448128872993657764,19198191503444720114404

%N Square numbers whose reverse is triangular with the same number of digits.

%C The sequence of corresponding triangular numbers is A066703. - _Robert G. Wilson v_, Jan 31 2011

%e 9446031 is triangular and 1306449 is a square.

%t lst = {0}; For[i = 1, i > 0, i++, s = i^2; t = FromDigits@ Reverse@ IntegerDigits@ s; If[ IntegerQ@ Sqrt[8 t + 1] && Mod[s, 10] > 0, AppendTo[lst, s]; Print@ lst]]

%Y Cf. A066703, A181412. - _Harvey P. Dale_, Jan 30 2011

%K base,more,nonn

%O 1,3

%A _Erich Friedman_, Jan 14 2002

%E a(12)-a(13) from and offset corrected by _Giovanni Resta_, Jun 20 2015

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Last modified March 29 09:44 EDT 2024. Contains 371268 sequences. (Running on oeis4.)