A072487 a(1) = 1, a(n) = a(n-1) times largest nontrivial divisor if n is composite.

1, 2, 6, 12, 60, 180, 1260, 5040, 15120, 75600, 831600, 4989600, 64864800, 454053600, 2270268000, 18162144000, 308756448000, 2778808032000, 52797352608000, 527973526080000, 3695814682560000, 40653961508160000

Offset

1,2

Comments

a(n) = n*a(n-1) if n is a prime.

Links

Table of n, a(n) for n=1..22.

Example

a(6)= 180 hence a(7) = 7*180 = 1260.

Crossrefs

Cf. A072486.

Sequence in context: A328522 A220027 A072489 * A309875 A254232 A335831

Adjacent sequences: A072484 A072485 A072486 * A072488 A072489 A072490

Keyword

nonn

Author

Amarnath Murthy, Jul 13 2002

Extensions

More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Apr 25 2003

Status

approved