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A032789 Numbers n such that (n*(n+1)*(n+2)) / (n+(n+1)+(n+2)) is a palindrome. 1
0, 1, 3, 4, 9, 21, 42, 99, 154, 237, 405, 999, 9999, 18991, 19291, 22021, 23587, 40293, 45072, 99999, 137652, 999999, 1278343, 1360456, 3162199, 3162499, 4029705, 4365396, 4418236, 6052891, 9999999 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Equivalently (2n+n^2)/3 is a palindrome. - Harvey P. Dale, Sep 02 2015

LINKS

Table of n, a(n) for n=1..31.

MATHEMATICA

palQ[n_]:=Module[{c=(2n+n^2)/3, id}, id=If[IntegerQ[c], IntegerDigits[c], {1, 2}]; id==Reverse[id]]; Select[Range[0, 10^7], palQ] (* Harvey P. Dale, Sep 02 2015 *)

CROSSREFS

Cf. A032790.

Sequence in context: A232955 A116868 A049976 * A089243 A299123 A245455

Adjacent sequences:  A032786 A032787 A032788 * A032790 A032791 A032792

KEYWORD

nonn,base

AUTHOR

Patrick De Geest, May 15 1998

EXTENSIONS

Definition clarified by Harvey P. Dale, Sep 02 2015

STATUS

approved

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Last modified May 19 20:41 EDT 2019. Contains 323410 sequences. (Running on oeis4.)