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 A179889 Triangular numbers whose reverse is a square (possibly with fewer digits). 6
 1, 10, 630, 52650, 165600, 986310, 9446031, 9485190, 10693000, 1270004401, 14214075921, 140884670790, 1809702709101, 4614899724711, 6766532724546, 9802814901400, 10210140486640, 14287075542460, 52657436563056, 98855178542676 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Giovanni Resta, Table of n, a(n) for n = 1..36 (terms < 2*10^24) EXAMPLE 9446031 is triangular and 1306449 is a square. MATHEMATICA trnos=Accumulate[Range[14070000]]; sqnoQ[n_]:=IntegerQ[Sqrt[FromDigits[Reverse[IntegerDigits[n]]]]] Select[trnos, sqnoQ] (* Harvey P. Dale, Jan 31 2011 *) CROSSREFS A variant of A066703. Cf. A069673, A181412, A066528. Sequence in context: A308145 A159622 A115692 * A209472 A132543 A261328 Adjacent sequences: A179886 A179887 A179888 * A179890 A179891 A179892 KEYWORD base,nonn AUTHOR Harvey P. Dale, Jan 30 2011 EXTENSIONS More terms from Harvey P. Dale, Jan 31 2011 STATUS approved

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Last modified December 9 06:02 EST 2023. Contains 367685 sequences. (Running on oeis4.)