A291000
p-INVERT of (1,1,1,1,1,...), where p(S) = 1 - S - S^2 - S^3.
Original entry on oeis.org
1, 3, 9, 26, 74, 210, 596, 1692, 4804, 13640, 38728, 109960, 312208, 886448, 2516880, 7146144, 20289952, 57608992, 163568448, 464417728, 1318615104, 3743926400, 10630080640, 30181847168, 85694918912, 243312448256, 690833811712, 1961475291648, 5569190816256
Offset: 0
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z = 60; s = x/(1 - x); p = 1 - s - s^2 - s^3;
Drop[CoefficientList[Series[s, {x, 0, z}], x], 1] (* A000012 *)
Drop[CoefficientList[Series[1/p, {x, 0, z}], x], 1] (* A291000 *)
A385178
Triangle T(n,k) read by rows in which the n-th diagonal lists the n-th differences of A001047, 0 <= k <= n.
Original entry on oeis.org
0, 1, 1, 3, 4, 5, 7, 10, 14, 19, 15, 22, 32, 46, 65, 31, 46, 68, 100, 146, 211, 63, 94, 140, 208, 308, 454, 665, 127, 190, 284, 424, 632, 940, 1394, 2059, 255, 382, 572, 856, 1280, 1912, 2852, 4246, 6305, 511, 766, 1148, 1720, 2576, 3856, 5768, 8620, 12866, 19171
Offset: 0
Triangle begins:
0;
1, 1;
3, 4, 5;
7, 10, 14, 19;
15, 22, 32, 46, 65;
31, 46, 68, 100, 146, 211;
63, 94, 140, 208, 308, 454, 665;
127, 190, 284, 424, 632, 940, 1394, 2059;
255, 382, 572, 856, 1280, 1912, 2852, 4246, 6305;
511, 766, 1148, 1720, 2576, 3856, 5768, 8620, 12866, 19171;
...
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/* As triangle */ [[2^(n-k)*3^k - 2^k : k in [0..n]]: n in [0..9]]; // Vincenzo Librandi, Jun 27 2025
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T:= proc(n,k) option remember;
`if`(n=k, 3^n-2^n, T(n, k+1)-T(n-1, k))
end:
seq(seq(T(n, k), k=0..n), n=0..10); # Alois P. Heinz, Jun 24 2025
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t[n_, 0] := 3^n - 2^n; t[n_, k_] := t[n, k] = t[n + 1, k - 1] - t[n, k - 1]; Table[t[k, n - k], {n, 0, 9}, {k, 0, n}] // Flatten (* Amiram Eldar, Jun 20 2025 *)
Showing 1-2 of 2 results.
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