

A259053


Number of triangles with sides pairwise relatively prime and one maximal side being n; permutations of sides are not considered distinct.


1



1, 0, 0, 0, 1, 0, 3, 2, 4, 1, 11, 2, 17, 6, 8, 9, 32, 6, 42, 12, 22, 15, 64, 12, 56, 25, 49, 25, 107, 12, 124, 51, 64, 45, 86, 27, 180, 59, 91, 45, 225, 30, 250, 81, 96, 87, 302, 55, 263, 82
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OFFSET

1,7


LINKS



MATHEMATICA

triangles[n_] := Module[{count = 0},
For[a = 1, a <= n, a++,
For[b = a, b <= n, b++,
If[(a + b > n) && CoprimeQ[a, b, n], count++]]];
count];
triangles[#] & /@ Range[50]


PROG

(PARI) a(n)=if(n==1, return(1)); sum(a=3, n2, if(gcd(a, n)==1, my(an=a*n); sum(b=max(a+1, na+1), n1, gcd(an, b)==1))) \\ Charles R Greathouse IV, Jun 29 2015


CROSSREFS



KEYWORD

nonn


AUTHOR



STATUS

approved



