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
Links
- Eric Weisstein's World of Mathematics, Pythagorean Triple
Crossrefs
Cf. A101929.
Programs
-
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
Formula
a(n) = A101929(n) + n. - Robert G. Wilson v, Mar 20 2014
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