A128295 a(n) = numerator of b(n): b(1)=1; b(n+1) = b(n) * [b(1);b(2),...,b(n)], where [...] is a continued fraction of rational terms.

1, 1, 2, 10, 560, 18393200, 11307340057302083200, 79095479027242971758816977525848827652668769392000

Offset

1,3

Comments

a(9) and a(10) have 131 and 343 digits, respectively and are too large to include here. - R. J. Mathar, Oct 08 2007

Links

Table of n, a(n) for n=1..8.

Example

a(5) = the numerator of b(5). b(5) = (10/3) * (1 +1/(1 +1/(2 +3/10))) = 560/99.

Maple

L2cfrac := proc(L) local a, i; a := op(-1, L) ; for i from 2 to nops(L) do a := op(-i, L)+1/a ; od: RETURN(a) ; end: A128295 := proc() local b, n, bnxt; b := [1] ; for n from 2 to 10 do bnxt := op(-1, b)*L2cfrac(b) ; b := [op(b), bnxt] ; od: [seq( numer(b[i]), i=1..nops(b))] ; end: A128295() ; # R. J. Mathar, Oct 08 2007

Crossrefs

Cf. A128296.

Sequence in context: A064300 A290060 A087754 * A089500 A246628 A028582

Adjacent sequences: A128292 A128293 A128294 * A128296 A128297 A128298

Keyword

frac,nonn

Author

Leroy Quet, Feb 25 2007

Extensions

More terms from R. J. Mathar, Oct 08 2007

Status

approved