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

%I

%S 1,2,3,11,127,16195,262286407,68794159432716139,

%T 4732636372053966959311918076028751,

%U 22397847030088134373054567592093233271179679420451463713205492138771

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

%C The next term (a(11)) has 135 digits. [From Harvey P. Dale, Feb 29 2012]

%e 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.

%Y Cf. A061902 (lengths of terms).

%K nonn,easy

%O 1,2

%A _Amarnath Murthy_, May 05 2001

%E More terms from Asher Auel (asher.auel(AT)reed.edu), May 05 2001. The 11th term has 135 digits.

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Last modified December 7 06:09 EST 2021. Contains 349567 sequences. (Running on oeis4.)