|
|
A010792
|
|
a(n) = n!*(n+3)! / 3!.
|
|
5
|
|
|
1, 4, 40, 720, 20160, 806400, 43545600, 3048192000, 268240896000, 28970016768000, 3766102179840000, 579979735695360000, 104396352425164800000, 21714441304434278400000, 5168037030455358259200000, 1395369998222946729984000000, 424192479459775805915136000000
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,2
|
|
LINKS
|
|
|
FORMULA
|
Sum_{n>=0} 1/a(n) = 6*BesselI(3,2) = 6*A261879.
Sum_{n>=0} (-1)^n/a(n) = 6*BesselJ(3,2). (End)
|
|
MAPLE
|
f := n->n!*(n+3)!/3!;
|
|
MATHEMATICA
|
|
|
PROG
|
(Magma) [Factorial(n)*Factorial(n+3)/6: n in [0..20]]; // Vincenzo Librandi, Feb 25 2017
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|