The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A341478 a(n) = sqrt( Product_{1<=j<=n-1} Product_{1<=k<=n} (4*sin(j*Pi/n)^2 + 4*sin((2*k-1)*Pi/(2*n))^2) ). 5
 1, 1, 6, 112, 6664, 1270016, 776239200, 1522266730496, 9580300901941376, 193509323594243571712, 12545297912843041612924416, 2610531939025273190037188509696, 1743627211475190637398673259679582208 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS Table of n, a(n) for n=0..12. FORMULA a(n) ~ exp(2*G*n^2/Pi) / 2^(3/4), where G is Catalan's constant A006752. - Vaclav Kotesovec, Feb 14 2021 MATHEMATICA Table[Sqrt[Product[4*Sin[j*Pi/n]^2 + 4*Sin[(2*k - 1)*Pi/(2*n)]^2, {k, 1, n}, {j, 1, n-1}]], {n, 0, 15}] // Round (* Vaclav Kotesovec, Feb 14 2021 *) PROG (PARI) default(realprecision, 120); a(n) = round(sqrt(prod(j=1, n-1, prod(k=1, n, 4*sin(j*Pi/n)^2+4*sin((2*k-1)*Pi/(2*n))^2)))); CROSSREFS Cf. A335586, A340562, A341479, A341493. Sequence in context: A296949 A009612 A009798 * A088668 A275924 A288561 Adjacent sequences: A341475 A341476 A341477 * A341479 A341480 A341481 KEYWORD nonn AUTHOR Seiichi Manyama, Feb 13 2021 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified August 11 23:45 EDT 2024. Contains 375082 sequences. (Running on oeis4.)