Original entry on oeis.org
1, -4, 144, -43264, 106832896, -2155963622400, 354617391605760000, -474686810341051524710400, 5166329306435680284163452174336, -456900249341808231214942590547243565056
Offset: 0
Original entry on oeis.org
1, 2, 4, 11, 53, 482, 7918, 226266, 11076482, 922911942, 130457184642, 31226202037017, 12642538061714517, 8652026056359367017, 10004193381504526849017, 19539080428042781631746217
Offset: 0
a(17) = 1 + 1 + 2 + 7 + 42 + 429 + 7436 + 218348 + 10850216 + 911835460 + 129534272700 + 31095744852375 + 12611311859677500 + 8639383518297652500 + 9995541355448167482000 + 19529076234661277104897200 + 64427185703425689356896743840 + 358869201916137601447486156417296.
Cf.
A005130,
A006366,
A048601, also
A003827,
A005156,
A005158,
A005160-
A005164,
A050204,
A049503,
A160707,
A160708.
-
Table[Sum[Product[(3 k + 1)!/(j + k)!, {k, 0, j - 1}], {j, 0, n}], {n, 0, 20}] (* Vaclav Kotesovec, Oct 26 2017 *)
Accumulate[Table[Product[(3k+1)!/(n+k)!,{k,0,n-1}],{n,0,20}]] (* Harvey P. Dale, Feb 06 2019 *)
A156106
Expansion of F(1/3,2/3;1/2;27*x/2) / F(1/3,-1/3;-1/2;27*x/2).
Original entry on oeis.org
1, 3, 15, 99, 783, 6987, 67671, 694035, 7418943, 81800091, 923720679, 10630297827, 124224709455, 1470172954347, 17585028636279, 212248303720371, 2581823992868703
Offset: 0
Comments