login
A055560
Base numbers of 9-gonal palindromic numbers.
4
1, 2, 6, 12, 17, 44, 74, 139, 1123, 1411, 2101, 4070, 11323, 11472, 12870, 16318, 16853, 18729, 52642, 132619, 435644, 446904, 168566853, 350096787, 521037077, 708609429, 1121857192, 1641773578, 11947307367, 21633254881, 75356090494
OFFSET
1,2
FORMULA
9-gonal numbers are of the form (n(7n-5))/2.
MATHEMATICA
Select[Range[0, 10^5], PalindromeQ[PolygonalNumber[9, #]] &] (* Robert Price, Apr 29 2019 *)
CROSSREFS
Sequence in context: A053457 A299112 A154030 * A237719 A369383 A108727
KEYWORD
nonn,base
AUTHOR
J. Lowell, Jul 10 2000
EXTENSIONS
Edited and extended by Patrick De Geest, Apr 13 2003.
STATUS
approved