A215755 Denominators of the continued fraction convergents of log_10(7).

1, 1, 6, 13, 71, 439, 510, 2455069, 2455579, 4910648, 12276875, 29464398, 71205671, 100670069, 171875740, 272545809, 1807150594, 9308298779, 11115449373, 931890596738, 6534349626539, 14000589849816, 20534939476355, 34535529326171, 55070468802526, 475099279746379, 2430566867534421

Offset: 0

Author

V. Raman, Aug 23 2012

Keywords

• nonn
• frac

Comments

7^a(n) gets increasingly close to 10^(numerator of convergent).

Crossrefs

Numerators are in A215759.

Cf. A046104, A073733, A082571, A153620.

Programs

Mathematica

Rest[Denominator[Convergents[Log[10,7],30]]] (* Harvey P. Dale, Aug 23 2013 *)

PARI

{my(cf=contfrac(log(7)/log(10))); vector(#cf, i, contfracpnqn( cf[1..i])[2, 1])}

Extensions

a(0)=1 prepended by Andrew Howroyd, Jul 09 2024