A249921 - cp's OEIS frontend

A249921 G.f.: Sum_{n>=0} x^n / (1-2x)^(2n+1) * [Sum_{k=0..n} C(n,k)^2 * 2^k * x^k] * [Sum_{k=0..n} C(n,k)^2 * 4^k * x^k].

n	a(n)
0	1
1	3
2	17
3	111
4	805
5	6147
6	48641
7	394863
8	3266629
9	27421395
10	232867889
11	1996302447
12	17248208485
13	150013649955
14	1312111499105
15	11532737017839
16	101799869875717
17	901975446062451
18	8018470050567953
19	71496291428776815
20	639204721160345509
21	5728606469731066947
22	51453397357702434497

[1, 3, 17, 111, 805, 6147, 48641, 394863, 3266629, 27421395, 232867889, 1996302447, 17248208485, 150013649955, 1312111499105, 11532737017839, 101799869875717, 901975446062451, 8018470050567953, 71496291428776815, 639204721160345509, 5728606469731066947, 51453397357702434497]

cp's OEIS Frontend

A249921 G.f.: Sum_{n>=0} x^n / (1-2x)^(2n+1) * [Sum_{k=0..n} C(n,k)^2 * 2^k * x^k] * [Sum_{k=0..n} C(n,k)^2 * 4^k * x^k].

Table of values

List of values

cp's OEIS Frontend

A249921 G.f.: Sum_{n>=0} x^n / (1-2*x)^(2*n+1) * [Sum_{k=0..n} C(n,k)^2 * 2^k * x^k] * [Sum_{k=0..n} C(n,k)^2 * 4^k * x^k].

Table of values

List of values

A249921 G.f.: Sum_{n>=0} x^n / (1-2x)^(2n+1) * [Sum_{k=0..n} C(n,k)^2 * 2^k * x^k] * [Sum_{k=0..n} C(n,k)^2 * 4^k * x^k].