A349270 a(n) = Sum_{k=0..n} (n - k)! * k! / floor(k / 2)!^2, row sums of A349269.
1, 2, 5, 16, 46, 204, 986, 6400, 48094, 420140, 4112822, 44575584, 528787260, 6811260792, 94637153172, 1410542965248, 22446384533142, 379801729831500, 6808478318116238, 128895044005636960, 2569653423591937156, 53808349548318974312, 1180737041228428129580
Offset: 0
Keywords
Links
- Seiichi Manyama, Table of n, a(n) for n = 0..449
Crossrefs
Cf. A349269.
Programs
-
Mathematica
Table[Sum[(n-k)! k! / Floor[k/2]!^2,{k,0,n}],{n,0,22}] (* Stefano Spezia, Nov 13 2021 *) -
PARI
a(n) = sum(k=0, n, (n - k)!*k!/(k\2)!^2); \\ Michel Marcus, Nov 13 2021