# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/

Search: id:a119437
Showing 1-1 of 1

%I A119437 #22 Mar 13 2020 19:51:19
%S A119437 6,12,8,48,4,10,108,16,4,12,248,36,4,4,14,428,64,20,4,4,16,764,100,44,
%T A119437 4,4,4,18,1196,204,36,24,4,4,4,20,1900,252,64,52,4,4,4,4,22,2668,396,
%U A119437 124,40,28,4,4,4,4,24,3824,572,200,20,60,4,4,4,4,4,26,5244,780,236,76,44,32
%N A119437 Table T(n,k) = number of lines through exactly k points of an n X n grid of points.
%H A119437 Seiichi Manyama, <a href="/A119437/b119437.txt">Rows n = 2..141, flattened</a>
%H A119437 S. Mustonen, <a href="http://www.survo.fi/papers/PointsInGrid.pdf">On lines and their intersection points in a rectangular grid of points</a> [From _Seppo Mustonen_, Apr 18 2009]
%H A119437 Seppo Mustonen, <a href="/A018808/a018808.pdf">On lines and their intersection points in a rectangular grid of points</a> [Local copy]
%F A119437 T(n,k) = 1/2 (f(n, k+1) - 2 f(n, k) + f(n, k-1)) where f(n, k) = Sum_{-n < kx < n, -n < ky < n, gcd(x, y)=1} (n - |kx|)*(n - |ky|). [_Seppo Mustonen_, Apr 18 2009]
%e A119437 From _Seiichi Manyama_, Nov 26 2017: (Start)
%e A119437 The table starts:
%e A119437   n\k|   2    3   4   5   6   7   8
%e A119437   ---+------------------------------
%e A119437    2 |   6;
%e A119437    3 |  12,   8;
%e A119437    4 |  48,   4, 10;
%e A119437    5 | 108   16,  4, 12;
%e A119437    6 | 248,  36,  4,  4, 14;
%e A119437    7 | 428,  64, 20,  4,  4, 16;
%e A119437    8 | 764, 100, 44,  4,  4,  4, 18; (End)
%Y A119437 Row sums A018808; columns A018809-A018817. See A119439 for another version.
%K A119437 nonn,tabl
%O A119437 2,1
%A A119437 _Franklin T. Adams-Watters_, May 19 2006
%E A119437 An incorrect formula removed by _Seppo Mustonen_, Apr 25 2009

# Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE