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A101929
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Number of Pythagorean triples with hypotenuse < 10^n.
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6
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1, 50, 878, 12467, 161431, 1980636, 23471468, 271360645, 3080075423, 34465432849, 381301109908, 4179478903380, 45459467009955, 491241450001314, 5278882299478781, 56453500988940599, 601181789833245614, 6378285697775544212
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OFFSET
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1,2
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COMMENTS
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There seems to be a relation between A101930 and this sequence: A101930(n) = n + a(n). - Jan Feitsma and Bart Dopheide (dopheide(AT)fmf.nl), Mar 10 2005
A101390(n) - a(n) = A046080(10^n). The formula listed for A046080 supports the relation of Jan Feitsma and Bart Dopheide: A046080(10^n) = n. - Frank Marcoline (fvmarcoline(AT)gmail.com), Dec 10 2008
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LINKS
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FORMULA
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PROG
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(PARI) a(n)=my(t, lim=10^n-1); 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 15 2012
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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More terms from Jan Feitsma and Bart Dopheide (dopheide(AT)fmf.nl), Mar 10 2005
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STATUS
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approved
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