A051848 - OEIS

%I #25 Oct 19 2022 06:44:08

%S 1,9,373,48913,13717421,6698798233,5057809205989,5465701947765793,

%T 8008631808527689309,15287592943577781017641,

%U 36867279706750843040346261,109619115381793714510485861169,393991653133258067890987154457613,1683967033137904529927995135566966713

%N Bisection of A023811, divided by the term position.

%F a(n) = A023811(2n)/(2n-1). [Corrected by _Alexander R. Povolotsky_, Oct 15 2022]

%F a(n) = A221741(2n-1). - _Alexander R. Povolotsky_, Oct 15 2022

%o (PARI) f(n) = (n^n-n^2)\(n-1)^2+1; \\ A023811

%o a(n) = f(2*n)/(2*n-1); \\ _Michel Marcus_, Oct 16 2022

%Y Cf. A023811, A051847, A221741.

%K easy,nonn

%O 1,2

%A _Antti Karttunen_, Dec 13 1999

%E a(13) and a(14) added by _Alexander R. Povolotsky_, Oct 16 2022