|
|
A094623
|
|
Expansion of g.f. x*(1+10*x)/((1-x)*(1-10*x^2)).
|
|
4
|
|
|
0, 1, 11, 21, 121, 221, 1221, 2221, 12221, 22221, 122221, 222221, 1222221, 2222221, 12222221, 22222221, 122222221, 222222221, 1222222221, 2222222221, 12222222221, 22222222221, 122222222221, 222222222221, 1222222222221
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,3
|
|
COMMENTS
|
Previous name was: Sequence whose n-th term digits sum to n.
n-th term digits are reversals of A094624(n).
|
|
LINKS
|
|
|
FORMULA
|
G.f.: x*(1+10*x)/((1-x)*(1-10*x^2)).
a(n) = (10^(n/2)/2)*(11/9 + 2*sqrt(10)/9 - (2*sqrt(10)/9 - 11/9)*(-1)^n) - 11/9.
E.g.f.: (11*(cosh(sqrt(10)*x) - cosh(x)) + 2*sqrt(10)*sinh(sqrt(10)*x) - 11*sinh(x))/9. - Stefano Spezia, Feb 21 2024
|
|
MATHEMATICA
|
LinearRecurrence[{1, 10, -10}, {0, 1, 11}, 30] (* Paolo Xausa, Feb 22 2024 *)
|
|
CROSSREFS
|
|
|
KEYWORD
|
easy,nonn,base
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|