A349970
a(n) = Sum_{k=0..n} (2*k)^(n-k).
Original entry on oeis.org
1, 1, 3, 9, 31, 125, 579, 3009, 17255, 108005, 731883, 5331625, 41501135, 343405709, 3007557523, 27775308049, 269603741111, 2742598070709, 29164361115067, 323444222468089, 3733412864370975, 44767318872513885, 556707323098632547, 7168524182698345313
Offset: 0
-
a[n_] := Sum[If[k == n == 0, 1, (2*k)^(n - k)], {k, 0, n}]; Array[a, 24, 0] (* Amiram Eldar, Dec 07 2021 *)
-
a(n) = sum(k=0, n, (2*k)^(n-k));
-
my(N=40, x='x+O('x^N)); Vec(sum(k=0, N, x^k/(1-2*k*x)))
A349962
a(n) = Sum_{k=0..n} (2*k)^k.
Original entry on oeis.org
1, 3, 19, 235, 4331, 104331, 3090315, 108503819, 4403471115, 202762761483, 10442762761483, 594761064172811, 37115108500229387, 2518267981703965963, 184577387811646500107, 14533484387811646500107, 1223459304002440821206283, 109651494909968373175414027
Offset: 0
-
a[n_] := Sum[If[k == 0, 1, (2*k)^k], {k, 0, n}]; Array[a, 18, 0] (* Amiram Eldar, Dec 07 2021 *)
-
a(n) = sum(k=0, n, (2*k)^k);
A368466
a(n) = Sum_{k=0..n} 2^k * k^n.
Original entry on oeis.org
1, 2, 18, 250, 4810, 118458, 3557610, 126109562, 5153959338, 238596116794, 12340467941098, 705262375055610, 44135963944338474, 3001795007526424250, 220466095716711140202, 17389850740043552754298, 1466156761178169939270826, 131580021359494993268692026
Offset: 0
A368270
a(n) = Sum_{k=0..n} 2^(n-k) * k^n.
Original entry on oeis.org
1, 1, 6, 47, 490, 6417, 101178, 1866139, 39425322, 938856053, 24883226698, 726510389607, 23169961642698, 801435579830329, 29884247978965146, 1195036047465095027, 51016725208899539626, 2315820594694418639325, 111384453953719146198762
Offset: 0
Showing 1-4 of 4 results.
Comments