A341900 - OEIS

%I #18 Dec 22 2024 21:32:30

%S 0,1,2,7,26,127,746,5167,41066,368047,3669866,40284847,482671466,

%T 6267305647,87660962666,1313941673647,21010450850666,357001369769647,

%U 6423384156578666,122002101778601647,2439325392333218666,51212944273488041647,1126440053169940898666

%N Partial sums of A005165.

%F a(n)-a(n-1) = A005165(n).

%F a(n) = Sum_{i=0..floor((n-1)/2)} (n-2*i)!.

%F a(n) = A136580(n) - A059841(n).

%F D-finite with recurrence a(n) -n*a(n-1) -a(n-2) +n*a(n-3)=0.

%F a(n) = n! + a(n-2) for n >= 2. - _Alois P. Heinz_, Jun 04 2021

%Y Cf. A000142, A005165, A136580, A215096.

%K nonn,easy

%O 0,3

%A _R. J. Mathar_, Jun 04 2021