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 A156665 Triangle read by rows, A156663 * A007318 2
 1, 1, 1, 3, 2, 1, 3, 5, 3, 1, 7, 8, 8, 4, 1, 7, 15, 16, 12, 5, 1, 15, 22, 31, 28, 17, 6, 1, 15, 37, 53, 59, 45, 23, 7, 1, 31, 52, 90, 112, 104, 68, 30, 8, 1, 31, 83, 142, 202, 216, 172, 98, 38, 9, 1, 63, 114, 225, 344, 418, 388, 270, 136, 47, 10, 1 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 0,4 COMMENTS Row sums = A122746: (1, 2, 6, 12, 28, 56, 120,...). LINKS Robert Israel, Table of n, a(n) for n = 0..10010 (first 141 rows, flattened) FORMULA Triangle read by rows, A156663 * A007318 G.f. for triangle: 1/((1-2*x^2)*(1-x-x*y)). - Robert Israel, Aug 10 2015 EXAMPLE First few rows of the triangle = 1; 1, 1; 3, 2, 1; 3, 5, 3, 1; 7, 8, 8, 4, 1; 7, 15, 16, 12, 5, 1; 15, 22, 31, 28, 17, 6, 1; 15, 37, 53, 59, 45, 23, 7, 1; 31, 52, 90, 112, 104, 68, 30, 8, 1; 31, 83, 142, 202, 216, 172, 98, 38, 9, 1; 63, 114, 225, 344, 418, 388, 270, 136, 47, 10, 1; ... MAPLE N:= 12: # for the first N rows A156663:= Matrix(N, N, (i, j) -> `if`((i-j)::even, 2^((i-j)/2), 0), shape=triangular[lower]): A007318:= Matrix(N, N, (i, j) -> binomial(i-1, j-1), shape=triangular[lower]): P:= A156663 . A007318: seq(seq(P[i, j], j=1..i), i=1..N); # Robert Israel, Aug 10 2015 CROSSREFS Sequence in context: A318582 A318317 A129690 * A215415 A244477 A035572 Adjacent sequences:  A156662 A156663 A156664 * A156666 A156667 A156668 KEYWORD nonn,tabl AUTHOR Gary W. Adamson, Feb 12 2009 STATUS approved

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Last modified May 23 11:01 EDT 2019. Contains 323513 sequences. (Running on oeis4.)