login
A082723
Palindromic nonagonal (or 9-gonal or enneagonal) numbers.
6
1, 9, 111, 474, 969, 6666, 18981, 67276, 4411144, 6964696, 15444451, 57966975, 448707844, 460595064, 579696975, 931929139, 994040499, 1227667221, 9698998969, 61556965516, 664248842466, 699030030996, 99451743334715499
OFFSET
1,2
MATHEMATICA
palQ[n_]:=Module[{idn=IntegerDigits[n]}, idn==Reverse[idn]]; Select[Table[ (n(7n-5))/2, {n, 170000000}], palQ] (* Harvey P. Dale, Nov 15 2011 *)
CROSSREFS
Sequence in context: A053904 A058607 A298835 * A352384 A143167 A201532
KEYWORD
nonn,base
AUTHOR
Patrick De Geest, Apr 13 2003
STATUS
approved