A061482 a(1) = 1, a(2) = 2, a(n) = sum of products of previous terms taking n-2 at a time.

1, 2, 3, 11, 127, 16195, 262286407, 68794159432716139, 4732636372053966959311918076028751, 22397847030088134373054567592093233271179679420451463713205492138771

Offset: 1

Author

Amarnath Murthy, May 05 2001

Keywords

• nonn
• easy
• changed

Comments

The next term (a(11)) has 135 digits. - Harvey P. Dale, Feb 29 2012

Examples

			a(3) = a(1) + a(2) = 3.
a(4) = a(1)*a(2) + a(2)*a(3) + a(3)*a(1) = 11.
a(5) = 1*2*3 + 1*2*11 + 1*3*11 + 2*3*11 = 127.
		

Crossrefs

Cf. A061902 (lengths of terms).

Extensions

More terms from Asher Auel, May 05 2001. The 11th term has 135 digits.