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 A295707 Square array A(n,k), n >= 1, k >= 1, read by antidiagonals, where A(n,k) is the number of lines through at least 2 points of an n X k grid of points. 10
 0, 1, 1, 1, 6, 1, 1, 11, 11, 1, 1, 18, 20, 18, 1, 1, 27, 35, 35, 27, 1, 1, 38, 52, 62, 52, 38, 1, 1, 51, 75, 93, 93, 75, 51, 1, 1, 66, 100, 136, 140, 136, 100, 66, 1, 1, 83, 131, 181, 207, 207, 181, 131, 83, 1, 1, 102, 164, 238, 274, 306, 274, 238, 164, 102, 1 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,5 LINKS Seiichi Manyama, Antidiagonals n = 1..140, flattened FORMULA A(n,k) = (1/2) * (f(n,k,1) - f(n,k,2)), where f(n,k,m) = Sum ((n-|m*x|)*(k-|m*y|)); -n < m*x < n, -k < m*y < k, (x,y)=1. EXAMPLE Square array begins:    0,  1,  1,   1,   1, ...    1,  6, 11,  18,  27, ...    1, 11, 20,  35,  52, ...    1, 18, 35,  62,  93, ...    1, 27, 52,  93, 140, ...    1, 38, 75, 136, 207, ... CROSSREFS Columns k=2..9 give A160842, A160843, A160844, A160845, A160846, A160847, A160848, A160849, A160850. Main diagonal gives A018808. Reading up to the diagonal gives A107348. Sequence in context: A046617 A131063 A081579 * A146772 A202868 A202877 Adjacent sequences:  A295704 A295705 A295706 * A295708 A295709 A295710 KEYWORD nonn,tabl AUTHOR Seiichi Manyama, Nov 26 2017 STATUS approved

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Last modified January 19 21:52 EST 2019. Contains 319310 sequences. (Running on oeis4.)