A101930 Number of Pythagorean triples with hypotenuse <= 10^n.

2, 52, 881, 12471, 161436, 1980642, 23471475, 271360653, 3080075432, 34465432859, 381301109919, 4179478903392, 45459467009968, 491241450001328, 5278882299478796, 56453500988940615, 601181789833245631, 6378285697775544230

Offset

1,1

Links

Table of n, a(n) for n=1..18.

Eric Weisstein's World of Mathematics, Pythagorean Triple

Formula

a(n) = A101929(n) + n. - Robert G. Wilson v, Mar 20 2014

Prog

(PARI) a(n)=my(t, lim=10^n); for(m=2, sqrtint(lim-1), forstep(n=1+m%2, min(sqrtint(lim-m^2), m-1), 2, if(gcd(m, n)==1, t+=lim\(m^2+n^2)))); t \\ Charles R Greathouse IV, Sep 13 2012

Crossrefs

Cf. A101929.

Sequence in context: A053317 A123803 A284767 * A297756 A174779 A215744

Adjacent sequences: A101927 A101928 A101929 * A101931 A101932 A101933

Keyword

nonn,more

Author

Eric W. Weisstein, Dec 21 2004

Extensions

Corrected by Todd Stedl (tstedl(AT)speakeasy.net), Jan 15 2005

More terms from Jan Feitsma and Bart Dopheide (dopheide(AT)fmf.nl), Mar 10 2005

a(10)-a(11) from Charles R Greathouse IV, Sep 14 2012

a(12) from Charles R Greathouse IV, Oct 15 2012

a(13)-a(17) from Hiroaki Yamanouchi, Jul 14 2014

a(18) from Matan M. Atzmoni, Feb 04 2023

Status

approved