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A176698 A symmetrical sum triangle sequence:a(n)=vector(a(n-1)).Reverse(vector(a(n-1));a(0)=1;a(1)=2;t(n,m)=2+a(n)-a(m)-a(n-m).

%I A176698 #4 Jun 02 2025 02:53:23
%S A176698 1,1,1,1,2,1,1,8,8,1,1,28,34,28,1,1,104,130,130,104,1,1,400,502,522,
%T A176698 502,400,1,1,1584,1982,2078,2078,1982,1584,1,1,6416,7998,8390,8466,
%U A176698 8390,7998,6416,1,1,26464,32878,34454,34826,34826,34454,32878,26464,1,1
%N A176698 A symmetrical sum triangle sequence:a(n)=vector(a(n-1)).Reverse(vector(a(n-1));a(0)=1;a(1)=2;t(n,m)=2+a(n)-a(m)-a(n-m).
%C A176698 Row sums are:
%C A176698 {1, 2, 4, 18, 92, 470, 2328, 11290, 54076, 257246, 1219296,...}.
%F A176698 a(n)=vector(a(n-1)).Reverse(vector(a(n-1));
%F A176698 a(0)=1;a(1)=2;\q t(n,m)=2+a(n)-a(m)-a(n-m)
%e A176698 {1},
%e A176698 {1, 1},
%e A176698 {1, 2, 1},
%e A176698 {1, 8, 8, 1},
%e A176698 {1, 28, 34, 28, 1},
%e A176698 {1, 104, 130, 130, 104, 1},
%e A176698 {1, 400, 502, 522, 502, 400, 1},
%e A176698 {1, 1584, 1982, 2078, 2078, 1982, 1584, 1},
%e A176698 {1, 6416, 7998, 8390, 8466, 8390, 7998, 6416, 1},
%e A176698 {1, 26464, 32878, 34454, 34826, 34826, 34454, 32878, 26464, 1},
%e A176698 {1, 110784, 137246, 143654, 145210, 145506, 145210, 143654, 137246, 110784, 1}
%t A176698 a[0] := 1; a[1] := 2;
%t A176698 a[n_] := a[n] = Table[a[i], {i, 0, n - 1}].Table[a[n - 1 - i], {i, 0, n - 1}];
%t A176698 t[n_, m_] := 2 + (-a[m] - a[n - m] + a[n]);
%t A176698 Table[Table[t[n, m], {m, 0, n}], {n, 0, 10}]
%Y A176698 Cf. A025227
%K A176698 nonn,tabl,uned
%O A176698 0,5
%A A176698 _Roger L. Bagula_, Apr 24 2010