A068857 a(0) = 0, a(1) = 8; for n>=2: a(n) = smallest multiple of a(n-1) which is of the form 2k*(2k+2).

0, 8, 24, 48, 288, 16128, 11950848, 4636929024, 88106288385024, 8038489644431643930624, 15177535939786079616000991061008232448, 40096515501441989312471498490435884509054125751527350190658560000

Offset

0,2

Links

Table of n, a(n) for n=0..11.

Formula

a(n) = 8 * A068776(n-1) for n>=1.

Example

24 = 4*6 is a member and the smallest multiple of 24 which is of the form 2k(2k+2) is 48 = 6*8.

Mathematica

m = 0; {0} ~Join~ Rest@ NestList[(m++; While[! Divisible[Set[k, # (# + 2) &[2 m]], #], m++]; k) &, 1, 8] (* Michael De Vlieger, Mar 18 2024 *)

Crossrefs

Cf. A000217, A033996, A068776.

Sequence in context: A028612 A333173 A358036 * A064225 A304844 A054275

Adjacent sequences: A068854 A068855 A068856 * A068858 A068859 A068860

Keyword

nonn

Author

Amarnath Murthy, Mar 12 2002

Extensions

More terms from Sascha Kurz, Mar 23 2002

a(8) onward corrected by Sean A. Irvine, Mar 18 2024

a(10)-a(11) from Alois P. Heinz, Mar 19 2024

Status

approved