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A115744 Triangular numbers that are the product of 2 palindromes greater than 1. 3
6, 10, 15, 21, 28, 36, 45, 55, 66, 231, 528, 666, 1128, 2016, 2211, 2628, 2775, 3003, 3570, 3916, 4095, 5995, 6105, 6216, 6903, 8646, 21736, 31878, 34980, 37950, 43956, 45753, 52003, 58653, 65703, 66066, 73153, 83028, 89676, 93528, 116886 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..83 (* All terms less than 1 million *)

EXAMPLE

6903=T(117) and 6903=9*767.

MATHEMATICA

Module[{upto=120000, pals}, pals=Select[Range[2, upto/2], PalindromeQ]; Select[ Times@@@Tuples[pals, 2], OddQ[Sqrt[8#+1]]&&#<=upto&]]//Union (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, May 13 2018 *)

CROSSREFS

Cf. A115683, A115743, A115745.

Sequence in context: A315278 A168102 A333296 * A211007 A315279 A122783

Adjacent sequences:  A115741 A115742 A115743 * A115745 A115746 A115747

KEYWORD

nonn,base

AUTHOR

Giovanni Resta, Jan 31 2006

STATUS

approved

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Last modified September 28 20:34 EDT 2022. Contains 357081 sequences. (Running on oeis4.)