|
|
A338795
|
|
Each term of A003215 (centered hexagonal numbers) is multiplied by the corresponding term of A003154 (centered dodecagonal numbers).
|
|
0
|
|
|
1, 91, 703, 2701, 7381, 16471, 32131, 56953, 93961, 146611, 218791, 314821, 439453, 597871, 795691, 1038961, 1334161, 1688203, 2108431, 2602621, 3178981, 3846151, 4613203, 5489641, 6485401, 7610851, 8876791, 10294453, 11875501, 13632031, 15576571, 17722081, 20081953
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
COMMENTS
|
The digital root (A010888) of each term is 1.
|
|
LINKS
|
|
|
FORMULA
|
a(n) = 18*n^4 - 36*n^3 + 27*n^2 - 9*n + 1.
|
|
EXAMPLE
|
The centered hexagonal number of 4 is 37, and the centered dodecagonal number of 4 is 73, so the fourth term of the series is [37 x 73] = 2701.
|
|
MATHEMATICA
|
LinearRecurrence[{5, -10, 10, -5, 1}, {1, 91, 703, 2701, 7381}, 40] (* Harvey P. Dale, May 13 2022 *)
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
_David Z. Crookes_, Nov 09 2020
|
|
STATUS
|
approved
|
|
|
|