A396933 - OEIS

%I #9 Jun 24 2026 18:48:36

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

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

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

%N Decimal expansion of the sum of the reciprocals of A202689.

%H Kelvin Voskuijl, <a href="/A396933/b396933.txt">Table of n, a(n) for n = 1..10000</a>

%F Equals hypergeom([], [1/2, 2], 1).

%e 2.11486811849536...

%t RealDigits[HypergeometricPFQ[{}, {1/2, 2}, 1], 10, 120][[1]]

%o (PARI) hypergeom([], [1/2, 2], 1)

%o (PARI) suminf(n=0, 1/((2*n)! * (n+1)! / 2^(2*n)))

%Y Cf. A202689.

%Y Cf. A001113, A070910, A271574, A396449, A396450, A396451, A396928, A396929, A396930, A396932, A396933.

%K nonn,cons

%O 1,1

%A _Kelvin Voskuijl_, Jun 17 2026