cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A273171 Triangle for numerators of coefficients for integrated odd powers of cos(x) in terms sin((2*m+1)*x).

Original entry on oeis.org

1, 3, 1, 5, 5, 1, 35, 7, 7, 1, 63, 7, 9, 9, 1, 231, 55, 33, 55, 11, 1, 429, 429, 143, 143, 13, 13, 1, 6435, 5005, 3003, 195, 455, 105, 15, 1, 12155, 2431, 1547, 221, 595, 85, 17, 17, 1, 46189, 12597, 12597, 969, 323, 969, 969, 57, 19, 1, 88179, 146965, 20349, 14535, 2261, 20349, 5985, 133, 105, 21, 1
Offset: 0

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Author

Wolfdieter Lang, Jun 13 2016

Keywords

Comments

The triangle for the denominators is given in A273172.
Int(cos^(2*n+1)(x), x) = Sum_{m = 0..n} R(n, m)*sin((2*m+1)*x), n >= 0, with the rational triangle a(n, m)/A273172(n, m).
For the rational triangle for the odd powers of cos see A244420/A244421. See also the odd-indexed rows of A273496.
The signed rational triangle S(n, m) = R(n, m)*(-1)^(m+1) appears in the formula
Int(sin^(2*n+1)(x), x) = Sum_{m = 0..n} S(n, m)*cos((2*m+1)*x), n >= 0,

Examples

			The triangle a(n, m) begins:
n\m    0     1     2   3   4   5   6  7  8 9
0:     1
1:     3     1
2:     5     5     1
3:    35     7     7   1
4:    63     7     9   9  1
5:   231    55    33  55  11   1
6:   429   429   143 143  13  13   1
7:  6435  5005  3003 195 455 105  15  1
8: 12155  2431  1547 221 595  85  17 17  1
9: 46189 12597 12597 969 323 969 969 57 19 1
...
row 10: 88179 146965 20349 14535 2261 20349 5985 133 105 21 1,
...
The rational triangle R(n, m) begins:
n\m   0    1     2    3      4     ...
0:   1/1
1:   3/4  1/12
2:   5/8  5/48 1/80
3:  35/64 7/64 7/320 1/448
4: 63/128 7/64 9/320 9/1792 1/2304
...
row 5: 231/512 55/512 33/1024 55/7168 11/9216 1/11264,
row 6: 429/1024 429/4096 143/4096 143/14336 13/6144 13/45056 1/53248,
row 7: 6435/16384 5005/49152 3003/81920 195/16384 455/147456 105/180224 15/212992 1/245760,
row 8: 12155/32768 2431/24576 1547/40960 221/16384 595/147456 85/90112 17/106496 17/983040 1/1114112,
row 9: 46189/131072 12597/131072 12597/327680 969/65536 323/65536 969/720896 969/3407872 57/1310720 19/4456448 1/4980736,
row 10: 88179/262144 146965/1572864 20349/524288 14535/917504 2261/393216 20349/11534336 5985/13631488 133/1572864 105/8912896 21/19922944 1/22020096.
...
n = 3: Int(cos^7(x), x) = (35/64)*sin(x) + (7/64)*sin(3*x) + (7/320)*sin(5*x) + (1/448)*sin(7*x). Gradstein-Rhyshik, p. 169, 2.513 16.
  Int(sin^7(x), x) = -(35/64)*cos(x) + (7/64)*cos(3*x) - (7/320)*cos(5*x) + (1/448)*cos(7*x). Gradstein-Rhyshik, p. 169, 2.513 10.
		

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 4.

Crossrefs

Programs

  • Mathematica
    T[MaxN_] :=   Function[{n}, With[{exp =  Expand[(1/2)^(2 n + 1) (Exp[I x] + Exp[-I x])^(2 n + 1)]},  2/(2 # + 1) Coefficient[exp, Exp[I (2 # + 1) x]] & /@  Range[0, n]]][#] & /@ Range[0, MaxN];
    T[5] // ColumnForm (* Bradley Klee, Jun 14 2016 *)
  • PARI
    a(n, m) = numerator((1/2^(2*n))*binomial(2*n+1, n-m)/(2*m+1));
    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) = (1/2^(2*n)) * binomial(2*n+1, n-m)/(2*m+1) for m = 0, ..., n, n >= 0. See the Gradstein-Ryshik reference (where the sin arguments are falling).