OFFSET
1,3
COMMENTS
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..75
M. R. Darafsheh, Hassan Jolany, An extension of Lobachevsky formula, arXiv:1004.2653 [math.GM], 2010-2017.
FORMULA
a(n) = A049330(2*n).
EXAMPLE
a(2) = 1 because Integral_{0..infinity} (sin(x)/x)^4 dx = (1/3)*Pi.
a(3) = 11 because Integral_{0..infinity} (sin(x)/x)^6 dx = (11/40)*Pi.
a(4) = 151 because Integral_{0..infinity} (sin(x)/x)^8 dx = (151/630)*Pi.
a(5) = 15619 because Integral_{0..infinity} (sin(x)/x)^10 dx = (15619/72576)*Pi.
MAPLE
A176365 := proc(n) sin(x)^(2*n)/x^(2*n) ; int(%, x=0..infinity)/Pi ; numer(%) ; end proc: # R. J. Mathar, Apr 24 2010
MATHEMATICA
a[n_]:= (1/Pi)*Integrate[(Sin[x]/x)^(2n), {x, 0, Infinity}]//Numerator; Array[a, 16] (* Jean-François Alcover, Nov 25 2017 *)
CROSSREFS
KEYWORD
frac,nonn
AUTHOR
Jonathan Vos Post, Apr 16 2010
EXTENSIONS
5 terms added and broken URL corrected by R. J. Mathar, Apr 24 2010
Further terms from Max Alekseyev, May 07 2010
STATUS
approved