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 A127445 Triangle defined by the matrix product A126988 * A127368, read by rows. 1
 1, 3, 0, 4, 2, 0, 7, 0, 3, 0, 6, 2, 3, 4, 0, 12, 4, 0, 0, 5, 0, 8, 2, 3, 4, 5, 6, 0, 15, 0, 9, 0, 5, 0, 7, 0, 13, 8, 0, 4, 5, 0, 7, 8, 0, 18, 4, 9, 8, 0, 0, 7, 0, 9, 0, 12, 2, 3, 4, 5, 6, 7, 8, 9, 10, 0, 28, 8, 9, 0, 15, 0, 7, 0, 0, 0, 11 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS FORMULA T(n,k) = Sum_{j=k..n} A126988(n,j) * A127368(j,k), 1<=k<=n. EXAMPLE First few rows of the triangle are: 1; 3, 0; 4, 2, 0; 7, 0, 3, 0; 6, 2, 3, 4, 0; 12, 4, 0, 0, 5, 0; 8, 2, 3, 4, 5, 6, 0; ... MAPLE A127368:=proc(n, k) if igcd(n, k) = 1 then k else 0 fi end: A127445 := proc(n, k)         add (A126988(n, j)*A127368(j, k), j=k..n) ; end proc: seq(seq(A127445(n, k), k=1..n), n=1..14) ; # R. J. Mathar, Nov 11 2011 CROSSREFS Cf. A126988, A127368, A000217 (row sums), A000203 (column k=1). Sequence in context: A003815 A306562 A131486 * A324025 A081170 A201291 Adjacent sequences:  A127442 A127443 A127444 * A127446 A127447 A127448 KEYWORD nonn,tabl AUTHOR Gary W. Adamson, Jan 14 2007 STATUS approved

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Last modified June 23 13:59 EDT 2021. Contains 345402 sequences. (Running on oeis4.)