Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #18 Jul 10 2019 11:16:53
%S 1,4,1,10,5,2,21,14,9,3,40,31,24,14,5,72,61,52,38,23,8,125,112,101,83,
%T 62,37,13,212,197,184,162,135,100,60,21,354,337,322,296,263,218,162,
%U 97,34,585,566,549,519,480,425,353,262,157,55,960,939,920,886
%N Rectangular array: (row n) = b**c, where b(h) = 2*n-1, c(h) = F(n-1+h), F=A000045 (Fibonacci numbers), n>=1, h>=1, and ** = convolution.
%C Principal diagonal: A213766.
%C Antidiagonal sums: A213767.
%C Row 1, (1,3,5,7,9,...)**(1,1,2,3,5,...): A001891.
%C Row 2, (1,3,5,7,9,...)**(1,2,3,5,8,...): A023652.
%C Row 3, (1,3,5,7,9,...)**(2,3,5,8,13,...).
%C For a guide to related arrays, see A213500.
%H Clark Kimberling, <a href="/A213765/b213765.txt">Antidiagonals n = 1..60, flattened</a>
%F T(n,k) = 3*T(n,k-1)-2*T(n,k-2)-T(n,k-3)+T(n,k-4).
%F G.f. for row n: f(x)/g(x), where f(x) = x*(F(n) + F(n+1)*x - F(n-1)*x^2) and g(x) = (1 - x - x^2)(1 - x )^2.
%F T(n,k) = F(n+k+4) - 2*k*F(n+1) - F(n+4), F = A000045. - _Ehren Metcalfe_, Jul 10 2019
%e Northwest corner (the array is read by falling antidiagonals):
%e 1....4....10....21....40....72
%e 1....5....14....31....61....112
%e 2....9....24....52....101...184
%e 3....14...38....83....162...296
%e 5....23...62....135...263...480
%e 8....37...100...218...425...776
%e 13...60...162...353...688...1256
%t b[n_] := 2 n - 1; c[n_] := Fibonacci[n];
%t t[n_, k_] := Sum[b[k - i] c[n + i], {i, 0, k - 1}]
%t TableForm[Table[t[n, k], {n, 1, 10}, {k, 1, 10}]]
%t Flatten[Table[t[n - k + 1, k], {n, 12}, {k, n, 1, -1}]]
%t r[n_] := Table[t[n, k], {k, 1, 60}] (* A213765 *)
%t Table[t[n, n], {n, 1, 40}] (* A213766 *)
%t s[n_] := Sum[t[i, n + 1 - i], {i, 1, n}]
%t Table[s[n], {n, 1, 50}] (* A213767 *)
%Y Cf. A213500.
%K nonn,tabl,easy
%O 1,2
%A _Clark Kimberling_, Jun 21 2012