A195531 - OEIS

A195531

Hypotenuses of Pythagorean triples in A195499 and A195503.

5, 17, 65, 241, 901, 3361, 12545, 46817, 174725, 652081, 2433601, 9082321, 33895685, 126500417, 472105985, 1761923521, 6575588101, 24540428881, 91586127425, 341804080817, 1275630195845, 4760716702561, 17767236614401, 66308229755041

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

See A195500 for discussion and list of related sequences; see A195499 for Mathematica program.

Essentially the same as A120893. - R. J. Mathar, Sep 21 2011

LINKS

Table of n, a(n) for n=1..24.

FORMULA

Conjecture: a(n) = 3*a(n-1)+3*a(n-2)-a(n-3). G.f.: x*(5+2*x-x^2)/((1+x)*(1-4*x+x^2)). - Colin Barker, Apr 08 2012

CROSSREFS

Cf. A195500, A195499, A195503.

Sequence in context: A273793 A196926 A120893 * A273535 A149672 A149673

Adjacent sequences: A195528 A195529 A195530 * A195532 A195533 A195534

KEYWORD

nonn

AUTHOR

Clark Kimberling, Sep 20 2011

STATUS

approved