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 A055894 Inverse Moebius transform of Pascal's triangle A007318. 2
 1, 1, 1, 2, 2, 2, 2, 3, 3, 2, 3, 4, 8, 4, 3, 2, 5, 10, 10, 5, 2, 4, 6, 18, 22, 18, 6, 4, 2, 7, 21, 35, 35, 21, 7, 2, 4, 8, 32, 56, 78, 56, 32, 8, 4, 3, 9, 36, 87, 126, 126, 87, 36, 9, 3, 4, 10, 50, 120, 220, 254, 220, 120, 50, 10, 4, 2, 11, 55, 165, 330, 462, 462, 330, 165, 55, 11 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 0,4 LINKS G. C. Greubel, Table of n, a(n) for the first 101 rows, flattened N. J. A. Sloane, Transforms EXAMPLE Triangle starts:   [0]  1;   [1]  1,   1;   [2]  2,   2,   2;   [3]  2,   3,   3,   2;   [4]  3,   4,   8,   4,   3;   [5]  2,   5,  10,  10,   5,   2;   [6]  4,   6,  18,  22,  18,   6,   4;   [7]  2,   7,  21,  35,  35,  21,   7,   2;   [8]  4,   8,  32,  56,  78,  56,  32,   8,   4;   [9]  3,   9,  36,  87, 126, 126,  87,  36,   9,   3;   ... MATHEMATICA T[n_, k_] := DivisorSum[GCD[k, n], Binomial[n/#, k/#] &]; T[0, 0] = 1; Table[T[n, k], {n, 0, 12}, {k, 0, n}] // Flatten (* Jean-François Alcover, Dec 02 2015 *) PROG (PARI) T(n, k) = if(n<=0, n==0, sumdiv(gcd(n, k), d, binomial(n/d, k/d) ) ); /* print triangle: */ { for (n=0, 17, for (k=0, n, print1(T(n, k), ", "); ); print(); ); } /* Joerg Arndt, Oct 21 2012 */ CROSSREFS Row sums give A055895. Sequence in context: A103183 A143901 A115263 * A224713 A168557 A194320 Adjacent sequences:  A055891 A055892 A055893 * A055895 A055896 A055897 KEYWORD nonn,tabl AUTHOR Christian G. Bower, Jun 09 2000 STATUS approved

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Last modified July 22 11:00 EDT 2019. Contains 325219 sequences. (Running on oeis4.)