A273169 Numerators of coefficient triangle for integrated even powers of cos(x) in terms of x and sin(2*m*x).
1, 1, 1, 3, 1, 1, 5, 15, 3, 1, 35, 7, 7, 1, 1, 63, 105, 15, 15, 5, 1, 231, 99, 495, 55, 33, 3, 1, 429, 3003, 1001, 1001, 91, 91, 7, 1, 6435, 715, 1001, 91, 455, 7, 5, 1, 1, 12155, 21879, 1989, 1547, 1071, 153, 17, 153, 9, 1, 46189, 20995, 62985, 1615, 4845, 969, 1615, 285, 95, 5, 1
Offset: 0
Examples
The triangle a(n, m) begins: n\m 0 1 2 3 4 5 6 7 8 9 0: 1 1: 1 1 2: 3 1 1 3: 5 15 3 1 4: 35 7 7 1 1 5: 63 105 15 15 5 1 6: 231 99 495 55 33 3 1 7: 429 3003 1001 1001 91 91 7 1 8: 6435 715 1001 91 455 7 5 1 1 9: 12155 21879 1989 1547 1071 153 17 153 9 1 ... row 10: 46189 20995 62985 1615 4845 969 1615 285 95 5 1, ... The rational triangle R(n, m) begins: n\m 0 1 2 3 4 ... 0: 1/1 1: 1/2 1/4 2: 3/8 1/4 1/32 3: 5/16 15/64 3/64 1/192 4: 35/128 7/32 7/128 1/96 1/1024 ... row 5: 63/256 105/512 15/256 15/1024 5/2048 1/5120, row 6: 231/1024 99/512 495/8192 55/3072 33/8192 3/5120 1/24576, row 7: 429/2048 3003/16384 1001/16384 1001/49152 91/16384 91/81920 7/49152 1/114688, row 8: 6435/32768 715/4096 1001/16384 91/4096 455/65536 7/4096 5/16384 1/28672 1/524288, row 9: 12155/65536 21879/131072 1989/32768 1547/65536 1071/131072 153/65536 17/32768 153/1835008 9/1048576 1/2359296, row 10: 46189/262144 20995/131072 62985/1048576 1615/65536 4845/524288 969/327680 1615/2097152 285/1835008 95/4194304 5/2359296 1/10485760, ... n = 3: Int(cos^6(x), x) = (5/16)*x + (15/64)*sin(2*x) + (3/64)*sin(4*x) + (1/192)*sin(6*x). Int(sin^6(x), x) = (5/16)*x - (15/64)*sin(2*x) + (3/64)*sin(4*x) - (1/192)*sin(6*x).
References
- I. S. Gradstein and I. M. Ryshik, Tables of series, products, and integrals, Volume 1, Verlag Harri Deutsch, 1981, pp. 168-169, 2.513 1. and 3.
Programs
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Mathematica
T[MaxN_] := Function[{n}, With[{exp = Expand[(1/2)^(2 n) (Exp[I x] + Exp[-I x])^(2 n)]}, Prepend[1/# Coefficient[exp, Exp[I 2 # x]] & /@ Range[1, n], exp /. {Exp[_] -> 0}]]][#] & /@ Range[0, MaxN]; T[5] // ColumnForm (* Bradley Klee, Jun 14 2016 *)
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PARI
a(n, m) = if (m == 0, numerator((1/2^(2*n))*binomial(2*n,n)), numerator((1/2^(2*n))*binomial(2*n, n-m)/m)); tabl(nn) = for (n=0, nn, for (k=0, n, print1(a(n,k), ", ")); print()); \\ Michel Marcus, Jun 19 2016
Formula
a(n, m) = numerator(R(n, m)) with the rationals R(n, m) defined by R(n, 0) = (1/2^(2*n))*binomial(2*n,n) and R(n, m) = (1/2^(2*n))*binomial(2*n, n-m)/m for m = 1, ..., n, n >= 0. See the Gradstein-Ryshik reference (where the sin arguments are falling).
Comments