A195557 Numerators b(n) of Pythagorean approximations b(n)/a(n) to 1/3.

0, 5, 7, 12, 155, 301, 444, 5921, 11395, 16872, 224807, 432745, 640680, 8536781, 16432879, 24328980, 324172835, 624016693, 923860548, 12310030985, 23696201419, 35082371856, 467457004559, 899831637265, 1332206269968, 17751056142293

Offset

1,2

Comments

See A195500 for discussion and list of related sequences; see A195556 for Mathematica program.

Links

Table of n, a(n) for n=1..26.

Formula

Conjecture: a(n) = +37*a(n-3) +37*a(n-6) -a(n-9). - R. J. Mathar, Sep 21 2011

Empirical g.f.: -x^2*(x^7-x^6-42*x^4+30*x^3-12*x^2-7*x-5) / (x^9-37*x^6-37*x^3+1). - Colin Barker, Jun 04 2015

Crossrefs

Cf. A195500, A195556, A195558.

Sequence in context: A020686 A011984 A280291 * A063187 A335164 A205323

Adjacent sequences: A195554 A195555 A195556 * A195558 A195559 A195560

Keyword

nonn

Author

Clark Kimberling, Sep 21 2011

Status

approved