A193649 Q-residue of the (n+1)st Fibonacci polynomial, where Q is the triangular array (t(i,j)) given by t(i,j)=1. (See Comments.)
1, 1, 3, 5, 15, 33, 91, 221, 583, 1465, 3795, 9653, 24831, 63441, 162763, 416525, 1067575, 2733673, 7003971, 17938661, 45954543, 117709185, 301527355, 772364093, 1978473511
Offset: 0
Keywords
A131056 A007318 * A131055.
1, 3, 7, 17, 41, 97, 225, 513, 1153, 2561, 5633, 12289, 26625, 57345, 122881, 262145, 557057, 1179649, 2490369, 5242881, 11010049, 23068673, 48234497, 100663297, 209715201, 436207617, 905969665
Offset: 1
Examples
a(4) = 17 = (1, 3, 3, 1) dot (1, 2, 2, 4) = (1 + 6 + 6 + 4).
Links
- Harvey P. Dale, Table of n, a(n) for n = 1..1000
- Index entries for linear recurrences with constant coefficients, signature (5,-8,4)
Programs
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Mathematica
LinearRecurrence[{5,-8,4},{1,3,7,17},40] (* Harvey P. Dale, Apr 30 2022 *)
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PARI
Vec(x*(1-2*x+2*x^3)/((1-x)*(1-2*x)^2)+O(x^99)) \\ Charles R Greathouse IV, Jun 12 2015
Formula
Binomial transform of A131055: (1, 2, 2, 4, 4, 6, 6, ...). A131056 = A131054 as an infinite lower triangular matrix * [1,2,3,...] as a vector.
G.f.: x*(1-2*x+2*x^3)/((1-x)*(1-2*x)^2); a(n)=-0^n/2+2^(n-1)*(n+1)+1. - Paul Barry, Jun 14 2008
a(n) = 2+A099035(n-1), n>1. - Juri-Stepan Gerasimov, Oct 02 2011
Extensions
More terms from Paul Barry, Jun 14 2008
A087322 Triangle T read by rows: T(n, 1) = 2*n + 1. For 1 < k <= n, T(n, k) = 2*T(n,k-1) + 1.
3, 5, 11, 7, 15, 31, 9, 19, 39, 79, 11, 23, 47, 95, 191, 13, 27, 55, 111, 223, 447, 15, 31, 63, 127, 255, 511, 1023, 17, 35, 71, 143, 287, 575, 1151, 2303, 19, 39, 79, 159, 319, 639, 1279, 2559, 5119, 21, 43, 87, 175, 351, 703, 1407, 2815, 5631, 11263, 23, 47, 95
Offset: 1
Comments
With T(n,0) = n for n >= 0, this becomes J. M. Bergot's triangular array in the definition of A190730. - Petros Hadjicostas, Feb 15 2021
Examples
Triangle T(n,k) (with rows n >= 1 and columns k = 1..n) begins: 3; 5, 11; 7, 15, 31; 9, 19, 39, 79; 11, 23, 47, 95, 191; 13, 27, 55, 111, 223, 447; 15, 31, 63, 127, 255, 511, 1023; 17, 35, 71, 143, 287, 575, 1151, 2303; 19, 39, 79, 159, 319, 639, 1279, 2559, 5119; ...
Links
- Paolo Xausa, Table of n, a(n) for n = 1..11325 (rows 1..150 of the triangle, flattened)
Programs
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Mathematica
A087322row[n_]:=NestList[2#+1&,2n+1,n-1];Array[A087322row,10] (* Paolo Xausa, Oct 17 2023 *)
Formula
T(n, k) = (n + 1)*2^k - 1 for n >= 1 and 1 <= k <= n.
From Petros Hadjicostas, Feb 15 2021: (Start)
Sum_{k=1..n} T(n,k) = A190730(n).
T(n,2) = 4*n + 3 for n >= 2.
T(n,n) = A087323(n).
T(n,n-1) = A099035(n) = (n+1)*2^(n-1) - 1 for n >= 2.
Recurrence: T(n,k) = 3*T(n,k-1) - 2*T(n,k-2) for n >= 2 and 2 <= k <= n with initial conditions the values of T(n, 1) and T(n,2).
Bivariate o.g.f.: Sum_{n,k>=1} T(n,k)*x^n*y^k = (4*x^3*y^2 - 2*x^2*y - 4*x*y - x + 3)*x*y/((1 - 2*x*y)^2*(1 - x*y)*(1 - x)^2). (End)
Extensions
Edited and extended by David Wasserman, May 06 2005
Name edited by Petros Hadjicostas, Feb 15 2021
A125026 Triangle read by rows: T(n,k) = k*binomial(n,k) + binomial(n-1,k) (1 <= k <= n).
1, 3, 2, 5, 7, 3, 7, 15, 13, 4, 9, 26, 34, 21, 5, 11, 40, 70, 65, 31, 6, 13, 57, 125, 155, 111, 43, 7, 15, 77, 203, 315, 301, 175, 57, 8, 17, 100, 308, 574, 686, 532, 260, 73, 9, 19, 126, 444, 966, 1386, 1344, 876, 369, 91, 10, 21, 155, 615, 1530, 2562, 2982, 2430, 1365
Offset: 1
Comments
Also A007318 * A127899 (unsigned) as a product of two infinite lower triangular matrices. - Gary W. Adamson, Feb 19 2007
Examples
First few rows of the triangle are 1; 3, 2; 5, 7, 3; 7, 15, 13, 4; 9, 26, 34, 21, 5; 11, 40, 70, 65, 31, 6; 13, 57, 125, 155, 111, 43, 7; ...
Crossrefs
Cf. A099035 (row sums).
Programs
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Maple
T:=(n,k)->k*binomial(n,k)+binomial(n-1,k): for n from 1 to 12 do seq(T(n,k),k=1..n) od; # yields sequence in triangular form
Extensions
Edited by N. J. A. Sloane, Nov 29 2006
A135852 A007318 * A103516 as a lower triangular matrix.
1, 3, 2, 8, 4, 3, 20, 6, 9, 4, 48, 8, 18, 16, 5, 112, 10, 30, 40, 25, 6, 256, 12, 45, 80, 75, 36, 7, 576, 14, 63, 140, 175, 126, 49, 8, 1280, 16, 84, 224, 350, 336, 196, 64, 9, 2816, 18, 108, 336, 630, 756, 588, 288, 81, 10
Offset: 0
Comments
Binomial transform of triangle A103516.
Examples
First few rows of the triangle are: 1; 3, 2; 8, 4, 3; 20, 6, 9, 4; 48, 8, 18, 16, 5; 112, 10, 30, 40, 25, 6; 256, 12, 45, 80, 75, 36, 7; ...
Links
- G. C. Greubel, Rows n = 0..50 of the triangle, flattened
Crossrefs
Programs
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Mathematica
T[n_, k_]:= If[n==0, 1, If[k==0, (n+2)*2^(n-1), (k+1)*Binomial[n, k]]]; Table[T[n, k], {n,0,12}, {k,0,n}]//Flatten (* G. C. Greubel, Dec 07 2016 *)
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Sage
def A135852(n,k): if (n==0): return 1 elif (k==0): return (n+2)*2^(n-1) else: return (k+1)*binomial(n, k) flatten([[A135852(n,k) for k in (0..n)] for n in (0..12)]) # G. C. Greubel, Feb 07 2022
Formula
T(n, 0) = A001792(n).
Sum_{k=0..n} T(n, k) = A099035(n+1).
T(n, k) = (k+1)*binomial(n, k), with T(n, 0) = (n+2)*2^(n-1), T(n, n) = n+1. - G. C. Greubel, Dec 07 2016
Extensions
Offset changed to 0 by G. C. Greubel, Feb 07 2022
A130295 Erroneous duplicate of A125026.
1, 3, 2, 5, 7, 3, 7, 15, 13, 4, 9, 26, 34, 21, 5, 11, 40, 70, 65, 31, 6, 13, 57, 125, 155, 111, 43, 7, 15, 77, 203, 315, 301, 175, 57, 8, 17, 100, 308, 574, 686, 532, 260, 73, 9, 19, 126, 444, 966, 1386, 1344, 876369, 91, 10
Offset: 1
Keywords
Comments
This sequence was initially defined as "A051340 * A007318". However, the matrix product A051340 * A007318 is not well defined, because all elements of A051340 are strictly positive integers, as are all elements of the lower left of A007318. Therefore the matrix A051340 must be truncated to its lower left (setting A[i,j]=0 if j>i), which actually equals A130296. Then the product yields this sequence, which is identical to A125026.
Examples
First few rows of the triangle A125026: 1; 3, 2; 5, 7, 3; 7, 15, 13, 4; 9, 26, 34, 21, 5; 11, 40, 70, 65, 31, 6; 13, 57, 125, 155, 111, 43, 7; ...
Formula
(A051340) * A007318 as infinite lower triangular matrices. [Here (A051340) is that matrix with the upper right triangle set to zero, which is actually A130296. - M. F. Hasler, Aug 15 2015]
Extensions
Restored and edited by M. F. Hasler, Aug 15 2015
A128224 Duplicate of A125026.
1, 3, 2, 5, 7, 3, 7, 15, 13, 4, 9, 26, 34, 21, 5, 11, 40, 70, 65, 31, 6, 13, 57, 125, 155, 111, 43, 7, 15, 77, 203, 315, 301, 175, 57, 8, 17, 100, 308, 574, 686, 532, 260, 73, 9, 19, 126, 444, 966, 1386, 876, 369, 91, 10
Offset: 1
Keywords
Comments
Row sums = A099035: (1, 5, 15, 39, 95, 223, 511, 1151, ...).
Examples
First few rows of the triangle: 1; 3, 2; 5, 7, 3; 7, 15, 13, 4; 9, 26, 34, 21, 5; 11, 40, 70, 65, 31, 6; 13, 57, 125, 155, 111, 43, 7; ...
A187214 Number of gulls (or G-toothpicks) added at n-th stage in the first quadrant of the gullwing structure of A187212.
0, 1, 1, 2, 2, 4, 5, 4, 2, 4, 6, 6, 8, 14, 15, 8, 2, 4, 6, 6, 8, 14, 16, 10, 8, 14, 18, 20, 30, 44, 39, 16, 2, 4, 6, 6, 8, 14, 16, 10, 8, 14, 18, 20, 30, 44, 40, 18, 8, 14, 18, 20, 30, 44, 42, 28, 30, 46, 56, 70, 104, 128, 95
Offset: 1
Keywords
Comments
It appears that both a(2) and a(2^k - 1) are odd numbers, for k >= 2. Other terms are even numbers.
Examples
At stage 1 we start in the first quadrant from a Q-toothpick centered at (1,0) with its endpoints at (0,0) and (1,1). There are no gulls in the structure, so a(1) = 0. At stage 2 we place a gull (or G-toothpick) with its midpoint at (1,1) and its endpoints at (2,0) and (2,2), so a(2) = 1. There is only one exposed midpoint at (2,2). At stage 3 we place a gull with its midpoint at (2,2), so a(3) = 1. There are two exposed endpoints. At stage 4 we place two gulls, so a(4) = 2. There are two exposed endpoints. At stage 5 we place two gulls, so a(5) = 2. There are four exposed endpoints. And so on. If written as a triangle begins: 0, 1, 1,2, 2,4,5,4, 2,4,6,6,8,14,15,8, 2,4,6,6,8,14,16,10,8,14,18,20,30,44,39,16, 2,4,6,6,8,14,16,10,8,14,18,20,30,44,40,18,8,14,18,20,30,44,42,28,... It appears that rows converge to A151688.
Links
- David Applegate, Omar E. Pol and N. J. A. Sloane, The Toothpick Sequence and Other Sequences from Cellular Automata, Congressus Numerantium, Vol. 206 (2010), 157-191. [There is a typo in Theorem 6: (13) should read u(n) = 4.3^(wt(n-1)-1) for n >= 2.]
- N. J. A. Sloane, Catalog of Toothpick and Cellular Automata Sequences in the OEIS
Programs
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Maple
read("transforms3") ; L := BFILETOLIST("b187212.txt") ; A187213 := DIFF(L) ; seq( op(n,A187213)/2,n=2..nops(A187213)) ; # R. J. Mathar, Mar 30 2011
Comments
Examples
Crossrefs
Programs
Mathematica
Formula