A118858 - OEIS

%I #22 Feb 16 2025 08:33:01

%S 0,7,0,2,3,0,4,9,2,7,7,2,6,8,2,8,7,6,4,0,8,9,3,8,5,9,9,4,9,6,9,9,7,0,

%T 0,9,6,3,2,8,7,6,5,3,2,4,4,3,2,6,2,5,4,1,3,7,7,4,3,4,3,7,8,2,2,8,2,4,

%U 9,6,4,1,3,3,6,9,6,8,5,3,4,0,1,4,2,0,1,6,9,3,5,8,0,7,3,3,4,0,0,9,4,3,2,7,6

%N Decimal expansion of log(2)/Pi^2.

%H Derrick Norman Lehmer, <a href="https://www.jstor.org/stable/2369728">Asymptotic Evaluation of Certain Totient Sums</a>, American Journal of Mathematics, Vol. 22, No. 4 (1900), pp. 293-335.

%H Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PrimitivePythagoreanTriple.html">Primitive Pythagorean Triple</a>.

%F Equals lim_{n->oo} A328499(n)/n. - _Amiram Eldar_, Jun 25 2021

%F Equals Integral_{z>=0} z*sech(Pi*z)^2. - _Peter Luschny_, Aug 03 2021

%e 0.07023049277268287640...

%t RealDigits[Log[2]/Pi^2, 10, 100][[1]] (* _Amiram Eldar_, Jun 25 2021 *)

%o (PARI) log(2)/Pi^2 \\ _Michel Marcus_, Jun 25 2021

%Y Cf. A249750, A328499, A002162, A002388, A284983.

%K nonn,cons,easy,changed

%O 0,2

%A _Eric W. Weisstein_, May 02 2006