A128294 a(n) = denominator 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, 16, 664, 5794064, 33447906751722, 27996871943383371722767277584, 1411648567276084801412872562665108454742185708848843396424

Offset

1,3

Comments

Next term a(10) has roughly 117 digits. - R. J. Mathar, Sep 24 2007

Links

Table of n, a(n) for n=1..9.

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: A128294 := 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( denom(b[i]), i=1..nops(b))] ; end: A128294() ; # R. J. Mathar, Sep 24 2007

Crossrefs

Cf. A128293.

Sequence in context: A277036 A289202 A279324 * A278087 A015188 A005118

Adjacent sequences: A128291 A128292 A128293 * A128295 A128296 A128297

Keyword

frac,nonn

Author

Leroy Quet, Feb 25 2007

Extensions

Corrected and extended by R. J. Mathar, Sep 24 2007

Status

approved