A270587 Denominators of r-Egyptian fraction expansion for 1/e, where r(k) = 1/(k+1).

2, 3, 37, 17282, 292943843, 105008217236608424, 15721030895760728441349083553863848, 293537352086847609928310098819595906620056713567902655641220410550838

Offset

1,1

Comments

Suppose that r is a sequence of rational numbers r(k) <= 1 for k >= 1, and that x is an irrational number in (0,1). Let f(0) = x, n(k) = floor(r(k)/f(k-1)), and f(k) = f(k-1) - r(k)/n(k). Then x = r(1)/n(1) + r(2)/n(2) + r(3)/n(3) + ... , the r-Egyptian fraction for x.

See A269993 for a guide to related sequences.

Links

Clark Kimberling, Table of n, a(n) for n = 1..11

Eric Weisstein's World of Mathematics, Egyptian Fraction

Index entries for sequences related to Egyptian fractions

Example

1/e = 1/(2*2) + 1/(3*3) + 1/(4*37) + 1/(5*17282) + ...

Mathematica

r[k_] := 1/(k+1); f[x_, 0] = x; z = 10;
n[x_, k_] := n[x, k] = Ceiling[r[k]/f[x, k - 1]]
f[x_, k_] := f[x, k] = f[x, k - 1] - r[k]/n[x, k]
x = 1/E; Table[n[x, k], {k, 1, z}]

Crossrefs

Cf. A269993.

Sequence in context: A221055 A144466 A245061 * A119448 A041329 A060813

Adjacent sequences: A270584 A270585 A270586 * A270588 A270589 A270590

Keyword

nonn,frac,easy

Author

Clark Kimberling, Apr 03 2016

Status

approved