Search: a364589 -id:a364589
|
| |
|
|
A364590
|
|
G.f. satisfies A(x) = 1/(1-x) + x^4*A(x)^3.
|
|
+10
2
|
|
|
|
1, 1, 1, 1, 2, 4, 7, 11, 19, 37, 74, 142, 268, 518, 1033, 2077, 4152, 8290, 16687, 33899, 69148, 141160, 288650, 592354, 1220086, 2519226, 5210164, 10794088, 22408556, 46613554, 97125751, 202662419, 423459427, 886048249, 1856448852, 3894362560, 8178530890
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
0,5
|
|
|
LINKS
|
|
|
|
FORMULA
|
a(n) = Sum_{k=0..floor(n/4)} binomial(n-2*k,2*k) * binomial(3*k,k) / (2*k+1).
|
|
|
PROG
|
(PARI) a(n) = sum(k=0, n\4, binomial(n-2*k, 2*k)*binomial(3*k, k)/(2*k+1));
|
|
|
CROSSREFS
|
|
|
|
KEYWORD
|
nonn,easy
|
|
|
AUTHOR
|
|
|
|
STATUS
|
approved
|
| |
|
|
| |
|
|
A369691
|
|
G.f. satisfies A(x) = 1/(1-x)^3 + x^3*A(x)^3.
|
|
+10
1
|
|
|
|
1, 3, 6, 11, 24, 66, 196, 576, 1692, 5110, 15933, 50604, 161988, 521700, 1693362, 5541679, 18260055, 60487659, 201272437, 672550158, 2256204327, 7596059333, 25655943417, 86904524289, 295154911774, 1004906765178, 3429178160346, 11726499288028, 40178538608682
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
0,2
|
|
|
LINKS
|
|
|
|
FORMULA
|
a(n) = Sum_{k=0..floor(n/3)} binomial(n+3*k+2,n-3*k) * binomial(3*k,k) / (2*k+1).
|
|
|
PROG
|
(PARI) a(n) = sum(k=0, n\3, binomial(n+3*k+2, n-3*k)*binomial(3*k, k)/(2*k+1));
|
|
|
CROSSREFS
|
|
|
|
KEYWORD
|
nonn
|
|
|
AUTHOR
|
|
|
|
STATUS
|
approved
|
| |
|
Search completed in 0.005 seconds
|
