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A193673
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Triangle given by p(n,k)=(coefficient of x^(n-k) in (1/2) ((x+3)^n+(x+1)^n)), 0<=k<=n.
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2
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1, 2, 1, 5, 4, 1, 14, 15, 6, 1, 41, 56, 30, 8, 1, 122, 205, 140, 50, 10, 1, 365, 732, 615, 280, 75, 12, 1, 1094, 2555, 2562, 1435, 490, 105, 14, 1, 3281, 8752, 10220, 6832, 2870, 784, 140, 16, 1, 9842, 29529, 39384, 30660, 15372, 5166, 1176, 180, 18, 1, 29525
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OFFSET
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0,2
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LINKS
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Table of n, a(n) for n=0..55.
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EXAMPLE
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First five rows:
1
2...1
5...4...1
14..15..6...1
41..56..30..8..1
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MATHEMATICA
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q[n_, k_] := 1; r[0] = 1;
r[k_] := Sum[q[k - 1, i] r[k - 1 - i], {i, 0, k - 1}]
p[n_, k_] := Coefficient[(1/2) ((x + 3)^n + (x + 1)^n), x, k] (* A193673 *)
v[n_] := Sum[p[n, k] r[n - k], {k, 0, n}]
Table[v[n], {n, 0, 20}] (* A193661 *)
TableForm[Table[q[i, k], {i, 0, 4}, {k, 0, i}]]
Table[r[k], {k, 0, 8}] (* 2^k *)
TableForm[Table[p[n, k], {n, 0, 10}, {k, 0, n}]] (* A193673 as a triangle *)
Flatten[%] (* A193673 as a sequence *)
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CROSSREFS
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Cf. A193661.
Sequence in context: A104710 A039598 A128738 * A126181 A154930 A104259
Adjacent sequences: A193670 A193671 A193672 * A193674 A193675 A193676
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KEYWORD
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nonn,tabl
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AUTHOR
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Clark Kimberling, Aug 02 2011
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STATUS
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approved
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