A208448 Greatest common divisors of consecutive floor-factorial numbers (A010786).

1, 1, 1, 2, 2, 6, 2, 8, 24, 60, 12, 288, 96, 84, 60, 3840, 384, 15552, 576, 14400, 20160, 221760, 576, 331776, 552960, 224640, 51840, 20321280, 2903040, 108864000, 345600, 17694720, 145981440, 51701760, 1935360, 11287019520, 1254113280, 2978519040, 10782720

Offset: 1

Author

Reinhard Zumkeller, Feb 26 2012

Keywords

• nonn

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A010786, A208449, A208450.

Programs

Haskell

a208448 n = a208448_list !! (n-1)
a208448_list = zipWith gcd a010786_list $ tail a010786_list

Mathematica

GCD @@@ Partition[#, 2, 1] & [Array[Product[Quotient[#, k], {k, #}] &, 30]] (* Paolo Xausa, Feb 11 2025 *)

PARI

f(n) = prod(k=1, n, n\k); \\ A010786
a(n) = gcd(f(n+1), f(n)); \\ Michel Marcus, Feb 03 2022

Formula

a(n) = GCD(A010786(n+1),A010786(n)).