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A195531
Hypotenuses of Pythagorean triples in A195499 and A195503.
3
5, 17, 65, 241, 901, 3361, 12545, 46817, 174725, 652081, 2433601, 9082321, 33895685, 126500417, 472105985, 1761923521, 6575588101, 24540428881, 91586127425, 341804080817, 1275630195845, 4760716702561, 17767236614401, 66308229755041
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
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
KEYWORD
nonn
AUTHOR
Clark Kimberling, Sep 20 2011
STATUS
approved