cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Previous Showing 11-20 of 27 results. Next

A136302 Transform of A000027 by the T_{1,1} transformation (see link).

Original entry on oeis.org

2, 6, 15, 35, 81, 188, 437, 1016, 2362, 5491, 12765, 29675, 68986, 160373, 372822, 866706, 2014847, 4683951, 10888865, 25313540, 58846841, 136802308, 318026782, 739322571, 1718716457, 3995531011, 9288482690, 21593102505, 50197873146, 116695897118, 271285047567
Offset: 1

Views

Author

Richard Choulet, Mar 22 2008

Keywords

Crossrefs

Programs

  • Magma
    I:=[2,6,15]; [n le 3 select I[n] else 3*Self(n-1) -2*Self(n-2) +Self(n-3): n in [1..41]]; // G. C. Greubel, Apr 12 2021
    
  • Maple
    a:= n-> (<<6|2|1>>. <<3|1|0>, <-2|0|1>, <1|0|0>>^n)[1, 3]:
    seq(a(n), n=1..40);  # Alois P. Heinz, Aug 14 2008
  • Mathematica
    LinearRecurrence[{3,-2,1}, {2,6,15}, 41] (* G. C. Greubel, Apr 12 2021 *)
  • Sage
    def A136302_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P( x*(2+x^2)/(1-3*x+2*x^2-x^3) ).list()
    a=A136302_list(41); a[1:] # G. C. Greubel, Apr 12 2021

Formula

G.f.: z*(2 + z^2)/(1 - 3*z + 2*z^2 - z^3).
a(n+3) = 3*a(n+2) - 2*a(n+1) + a(n) (n>=0). - Richard Choulet, Apr 07 2009
a(n) = 2*A095263(n) + A095263(n-2). - R. J. Mathar, Feb 29 2016

Extensions

More terms from Alois P. Heinz, Aug 14 2008

A136303 Expansion of g.f. (1 +x^2)/((1-x)^2*(1 -3*x +2*x^2 -x^3)).

Original entry on oeis.org

1, 5, 17, 48, 123, 300, 714, 1679, 3925, 9149, 21296, 49537, 115192, 267824, 622653, 1447533, 3365149, 7823068, 18186475, 42278476, 98285586, 228486323, 531166317, 1234811937, 2870589548, 6673311137, 15513566304, 36064666240, 83840177305
Offset: 0

Views

Author

Richard Choulet, Mar 22 2008

Keywords

Comments

Previous name: Transform of 0 by the reciprocal transformation to T_{1,1} (see link).

Crossrefs

Programs

  • Magma
    R:=PowerSeriesRing(Integers(), 40); Coefficients(R!( (1+x^2)/((1-x)^2*(1-3*x+2*x^2-x^3)) )); // G. C. Greubel, Apr 19 2021
    
  • Maple
    A136303:= n-> -2*(n+2) + add( (5*binomial(n+k+2, 3*k+2) - 4*binomial(n +k+1, 3*k+2) + 2*binomial(n+k, 3*k+2)), k=0..n/2 );
    seq(A136303(n), n=0..40); # G. C. Greubel, Apr 19 2021
  • Mathematica
    LinearRecurrence[{5,-9,8,-4,1},{1,5,17,48,123},40] (* Harvey P. Dale, Apr 01 2018 *)
  • Sage
    def A136303_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P( (1+x^2)/((1-x)^2*(1-3*x+2*x^2-x^3)) ).list()
    A136303_list(40) # G. C. Greubel, Apr 19 2021

Formula

G.f.: f(z) = 1 +5*z + ... = (1+z^2)/((1-z)^2*(1-3*z+2*z^2-z^3)).
a(n+5) = 5*a(n+4) -9*a(n+3) +8*a(n+2) -4*a(n+1) +a(n) (n>=0). - Richard Choulet, Apr 07 2009
From G. C. Greubel, Apr 19 2021: (Start)
a(n) = -2*(n+2) + 5*A095263(n) - 4*A095263(n-1) + 2*A095263(n-2).
a(n) = -2*(n+2) + Sum_{k=0..floor(n/2)} (5*binomial(n+k+2, 3*k+2) - 4*binomial(n +k+1, 3*k+2) + 2*binomial(n+k, 3*k+2)). (End)

A137229 Expansion of g.f. x/((1-x)*(1-3*x+2*x^2-x^3)).

Original entry on oeis.org

1, 4, 11, 27, 64, 150, 350, 815, 1896, 4409, 10251, 23832, 55404, 128800, 299425, 696080, 1618191, 3761839, 8745216, 20330162, 47261894, 109870575, 255418100, 593775045, 1380359511, 3208946544, 7459895656, 17342153392, 40315615409, 93722435100, 217878227875
Offset: 1

Views

Author

Richard Choulet, Apr 05 2008

Keywords

Comments

Previous name was: Transform of A000217 without the initial 0 by the T_{0,0} transformation (see link).
Partial sums of A095263. - R. J. Mathar, Nov 04 2008

Crossrefs

Programs

  • Magma
    I:=[1,4,11,27]; [n le 4 select I[n] else 4*Self(n-1) -5*Self(n-2) +3*Self(n-3) -Self(n-4): n in [1..40]]; // G. C. Greubel, Apr 17 2021
    
  • Maple
    a:= n-> (<<3|1|0|0>, <-2|0|1|0>, <1|0|0|0>, <1|0|0|1>>^n)[4, 1]:
    seq(a(n), n=1..50);  # Alois P. Heinz, Jul 24 2008
  • Mathematica
    LinearRecurrence[{4,-5,3,-1},{1,4,11,27},40] (* Harvey P. Dale, Nov 10 2014 *)
  • Sage
    def A137229_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P( x/((1-x)*(1-3*x+2*x^2-x^3)) ).list()
    a=A137229_list(41); a[1:] # G. C. Greubel, Apr 17 2021

Formula

O.g.f: x/((1-x)*(1 -3*x +2*x^2 -x^3)).
a(n) = term (4,1) in the 4x4 matrix [3,1,0,0; -2,0,1,0; 1,0,0,0; 1,0,0,1]^(n). - Alois P. Heinz, Jul 24 2008

Extensions

New name using g.f., Joerg Arndt, Apr 18 2021

A368475 Expansion of o.g.f. (1-x)^5/((1-x)^5 - x^4).

Original entry on oeis.org

1, 0, 0, 0, 1, 5, 15, 35, 71, 136, 265, 550, 1211, 2732, 6126, 13485, 29191, 62648, 134408, 289656, 627401, 1363124, 2963186, 6434484, 13951852, 30221185, 65442625, 141745045, 307137901, 665732417, 1443184210, 3128438335, 6780867186, 14696002913, 31848721632
Offset: 0

Views

Author

Enrique Navarrete, Dec 26 2023

Keywords

Comments

For n > 0, a(n) is the number of ways to split [n] into an unspecified number of intervals and then choose 4 blocks (i.e., subintervals) from each interval. For example, for n=12, a(12)=1211 since the number of ways to split [12] into intervals and then select 4 blocks from each interval is C(12,4) + C(8,4)*C(4,4) + C(7,4)*C(5,4) + C(6,4)*C(6,4) + C(5,4)*C(7,4) + C(4,4)*C(8,4) + C(4,4)*C(4,4)*C(4,4) for a total of 1211 ways.
For n > 0, a(n) is also the number of compositions of n using parts of size at least 4 where there are binomial(i,4) types of i, i >= 4 (see example).
Number of compositions of 5*n-4 into parts 4 and 5. - Seiichi Manyama, Feb 01 2024

Examples

			Since there are C(4,4) = 1 type of 4, C(5,4) = 5 types of 5, C(6,4) = 15 types of 6, C(7,4) = 35 types of 7, C(8,4) = 70 types of 8, and (12,4) = 495 types of 12, we can write 12 in the following ways:
  12: 495 ways;
  8+4: 70 ways;
  7+5: 175 ways;
  6+6: 225 ways;
  5+7: 175 ways;
  4+8: 70 ways;
  4+4+4: 1 way, for a total of 1211 ways.
		

Crossrefs

Programs

  • Mathematica
    CoefficientList[Series[(1 - x)^5/((1 - x)^5 - x^4), {x, 0, 50}], x] (* Wesley Ivan Hurt, Dec 26 2023 *)
  • PARI
    Vec((1-x)^5/((1-x)^5 - x^4) + O(x^40)) \\ Michel Marcus, Dec 27 2023

Formula

a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 4*a(n-4) + a(n-5), n>=6; a(0)=1, a(1)=a(2)=a(3)=0, a(4)=1, a(5)=5.
G.f.: 1/(1-Sum_{k>=4} binomial(k,4)*x^k).
G.f.: 1/p(S), where p(S) = 1 - S^4 - S^5 and S = x/(1-x).
First differences of A099131. - R. J. Mathar, Jan 29 2024
a(n) = A017827(5*n-4) = Sum_{k=0..floor((5*n-4)/4)} binomial(k,5*n-4-4*k) for n > 0. - Seiichi Manyama, Feb 01 2024
a(n) = Sum_{k=0..floor(n/4)} binomial(n-1+k,n-4*k). - Seiichi Manyama, Feb 02 2024

A127893 Riordan array (1/(1-x)^3, x/(1-x)^3).

Original entry on oeis.org

1, 3, 1, 6, 6, 1, 10, 21, 9, 1, 15, 56, 45, 12, 1, 21, 126, 165, 78, 15, 1, 28, 252, 495, 364, 120, 18, 1, 36, 462, 1287, 1365, 680, 171, 21, 1, 45, 792, 3003, 4368, 3060, 1140, 231, 24, 1, 55, 1287, 6435, 12376, 11628, 5985, 1771, 300, 27, 1
Offset: 0

Views

Author

Paul Barry, Feb 04 2007

Keywords

Comments

Inverse is A127894.
From Peter Bala, Jul 22 2014: (Start)
Let M denote the unsigned version of the lower unit triangular array A122432 and for k = 0,1,2,... define M(k) to be the lower unit triangular block array
/I_k 0\
\ 0 M/
having the k x k identity matrix I_k as the upper left block; in particular, M(0) = M. Then the present triangle equals the infinite matrix product M(0)*M(1)*M(2)*... (which is clearly well-defined). See the Example section. (End)

Examples

			Triangle begins
   1;
   3,    1;
   6,    6,     1;
  10,   21,     9,     1;
  15,   56,    45,    12,     1;
  21,  126,   165,    78,    15,     1;
  28,  252,   495,   364,   120,    18,     1;
  36,  462,  1287,  1365,   680,   171,    21,    1;
  45,  792,  3003,  4368,  3060,  1140,   231,   24,   1;
  55, 1287,  6435, 12376, 11628,  5985,  1771,  300,  27,  1;
  66, 2002, 12870, 31824, 38760, 26334, 10626, 2600, 378, 30, 1;
  ...
From _Peter Bala_, Jul 22 2014: (Start)
With the arrays M(k) as defined in the Comments section, the infinite product M(0*)M(1)*M(2)*... begins
  / 1         \/1         \/1       \       / 1       \
  | 3  1      ||0  1      ||0 1      |      | 3  1    |
  | 6  3 1    ||0  3 1    ||0 0 1    |... = | 6  6 1  |
  |10  6 3 1  ||0  6 3 1  ||0 0 3 1  |      |10 21 9 1|
  |15 10 6 3 1||0 10 6 3 1||0 0 6 3 1|      |...      |
  |...        ||...       ||...      |      |...      |
(End)
		

Crossrefs

Programs

  • GAP
    Flat(List([0..10],n->List([0..n],k->Binomial(n+2*k+2,n-k)))); # Muniru A Asiru, Apr 30 2018
    
  • Magma
    [Binomial(n+2*k+2, n-k): k in [0..n], n in [0..10]]; // G. C. Greubel, Apr 29 2018
    
  • Maple
    seq(seq(binomial(n+2*k+2,n-k),k=0..n),n=0..10); # Robert Israel, Apr 28 2015
  • Mathematica
    Flatten@ Table[Binomial[n+2k-1, n-k], {n, 10}, {k, n}] (* Michael De Vlieger, Apr 27 2015 *)
  • PARI
    for(n=0,10, for(k=0,n, print1(binomial(n+2*k+2, n-k), ", "))) \\ G. C. Greubel, Apr 29 2018
    
  • Sage
    flatten([[binomial(n+2*k+2,n-k) for k in (0..n)] for n in (0..12)]) # G. C. Greubel, Apr 16 2021

Formula

T(n,k) = binomial(n+2*k+2, n-k).
Sum_{k=0..n} T(n, k) = A052529(n+1) (row sums).
Sum_{k=0..floor(n/2)} T(n-k, k) = A095263(n+1) (diagonal sums).
Recurrence: T(n+1, k+1) = Sum_{i = 0..n-k} binomial(i+2, 2)*T(n-i,k). - Peter Bala, Jul 22 2014
G.f.: 1/((1-x)^3-x*y). - Vladimir Kruchinin, Apr 27 2015

A137234 Expansion of g.f. 1/((1-x)^2*(1 - 3*x + 2*x^2 - x^3)).

Original entry on oeis.org

1, 5, 16, 43, 107, 257, 607, 1422, 3318, 7727, 17978, 41810, 97214, 226014, 525439, 1221519, 2839710, 6601549, 15346765, 35676927, 82938821, 192809396, 448227496, 1042002541, 2422362052, 5631308596, 13091204252, 30433357644, 70748973053
Offset: 0

Views

Author

Richard Choulet, Apr 05 2008

Keywords

Comments

Previous name: Transform of A000292 without the initial 0 by the T_{0,0} transformation (see link).
Partial sums of A137229. - R. J. Mathar, Nov 04 2008

Crossrefs

Programs

  • Magma
    I:=[1,5,16,43,107]; [n le 5 select I[n] else 5*Self(n-1) -9*Self(n-2) +8*Self(n-3) -4*Self(n-4) +Self(n-5): n in [1..41]]; // G. C. Greubel, Apr 19 2021
    
  • Mathematica
    LinearRecurrence[{5,-9,8,-4,1}, {1,5,16,43,107}, 41] (* G. C. Greubel, Apr 19 2021 *)
    CoefficientList[Series[1/((1-x)^2(1-3x+2x^2-x^3)),{x,0,30}],x] (* Harvey P. Dale, Jun 07 2021 *)
  • Sage
    @CachedFunction
    def A095263(n): return sum(binomial(n+j+2, 3*j+2) for j in (0..n//2))
    def A137234(n): return -(n+3) + sum( (-1)^j*(4-j)*A095263(n-j) for j in (0..2))
    [A137234(n) for n in (0..40)] # G. C. Greubel, Apr 19 2021

Formula

O.g.f: 1/((1-z)^2*(1 - 3*z + 2*z^2 - z^3)).
a(n) = -(n+3) + Sum_{j=0..2} (-1)^j*(4-j)*A095263(n-j). - G. C. Greubel, Apr 19 2021

A137249 Expansion of g.f. z*(2-2*z+z^2+z^3)/((1+z)*(1-3*z+2*z^2-z^3)).

Original entry on oeis.org

2, 2, 7, 15, 37, 84, 197, 456, 1062, 2467, 5737, 13335, 31002, 72069, 167542, 389486, 905447, 2104907, 4893317, 11375580, 26445017, 61477204, 142917162, 332242091, 772369157, 1795540447, 4174125122, 9703663625, 22558281082
Offset: 1

Views

Author

Richard Choulet, Apr 05 2008

Keywords

Comments

Previous name was: Transform of A033999 by the T_{0,1} transformation (see link).

Crossrefs

Programs

  • Magma
    R:=PowerSeriesRing(Integers(), 40);
    Coefficients(R!( (2-2*x+x^2+x^3)/((1+x)*(1-3*x+2*x^2-x^3)) )); // G. C. Greubel, Apr 11 2021
    
  • Maple
    m:= 40;
    S:= series( x*(2-2*x+x^2+x^3)/((1+x)*(1-3*x+2*x^2-x^3)), x, m+1);
    seq(coeff(S, x, j), j = 1..m); # G. C. Greubel, Apr 11 2021
  • Mathematica
    LinearRecurrence[{2,1,-1,1},{2,2,7,15},30] (* Harvey P. Dale, Feb 02 2012 *)
  • Sage
    def A132749_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P( (2-2*x+x^2+x^3)/((1+x)*(1-3*x+2*x^2-x^3)) ).list()
    A132749_list(40) # G. C. Greubel, Apr 11 2021

Formula

O.g.f: z*(2 -2*z +z^2 +z^3)/( (1+z)*(1-3*z+2*z^2-z^3) ).
a(n+4) = 2*a(n+3) + a(n+2) - a(n+1) + a(n).
From G. C. Greubel, Apr 11 2021: (Start)
a(n) = (4*(-1)^n + 10*A095263(n) - 12*A095263(n-1) + 11*A095263(n-2))/7.
a(n) = (1/7)*( 4*(-1)^n + Sum_{j=0..floor(n/2)} ( 10*binomial(n+j+2, 3*j+2) - 12*binomial(n+j+1, 3*j+2) + 11*binomial(n+j, 3*j+2) ) ). (End)

Extensions

New name using g.f. from Joerg Arndt, Apr 19 2021

A369794 Expansion of 1/(1 - x^5/(1-x)^6).

Original entry on oeis.org

1, 0, 0, 0, 0, 1, 6, 21, 56, 126, 253, 474, 870, 1651, 3367, 7372, 16762, 38183, 85290, 185573, 394555, 826752, 1724816, 3613968, 7642004, 16313856, 35052905, 75487110, 162349105, 348018300, 743376838, 1583718457, 3370144462, 7173308802, 15285181447
Offset: 0

Views

Author

Seiichi Manyama, Feb 01 2024

Keywords

Comments

Number of compositions of 6*n-5 into parts 5 and 6.

Crossrefs

Programs

  • PARI
    my(N=40, x='x+O('x^N)); Vec(1/(1-x^5/(1-x)^6))

Formula

a(n) = A107025(n)-A107025(n-1). First differences of A107025.
a(n) = A017837(6*n-5) = Sum_{k=0..floor((6*n-5)/5)} binomial(k,6*n-5-5*k) for n > 0.
a(n) = 6*a(n-1) - 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 7*a(n-5) - a(n-6) for n > 6.
a(n) = Sum_{k=0..floor(n/5)} binomial(n-1+k,n-5*k).

A096261 Number of n-tuples of 0,1,2,3,4,5,6,7,8,9 without consecutive digits.

Original entry on oeis.org

1, 10, 91, 828, 7534, 68552, 623756, 5675568, 51642104, 469892512, 4275561136, 38903414208, 353982925023, 3220897542254, 29307009588171, 266665052127080, 2426390512890816, 22077774624328776, 200886102122914612
Offset: 0

Views

Author

Seppo Mustonen, Aug 01 2004

Keywords

Comments

Sketch of a proof for a general base b >= 2: Let a(n) be the number of n-tuples of 0, 1, ..., b-1 without consecutive digits and s(n,i) the number of them with i (i = 0, 1, ..., b-1) as the last digit. Then it is clear that s(n,i) = a(n-1) - s(n-1, i-1) since when extending a valid n-1-tuple with i those ending with i-1 are not valid as n-tuples.
Thus s(n,0) = a(n-1), s(n,1) = a(n-1) - s(n-1,0) = a(n-1) - a(n-2) and in general s(n,i) = a(n-1) - a(n-2) + a(n-3) - ... + (-1)^i*a(n-i-1), i = 0, 1, ..., b-1. Since a(n) = Sum_{j=0..b-1} s(n,j), we get the recursion formula a(n) = b*a(n-1) -( b-1)*a(n-2) + (b-2)*a(n-3) - ... + (-1)^(b-1)*a(n-b).

Crossrefs

Case b=3 is A095263.
Column k=10 of A277666.

Programs

  • Magma
    R:=PowerSeriesRing(Integers(), 30);
    Coefficients(R!( 1/(1-10*x+9*x^2-8*x^3+7*x^4-6*x^5+5*x^6-4*x^7+3*x^8-2*x^9+x^10) )); // G. C. Greubel, Apr 17 2021
    
  • Maple
    A096261:=proc(n,b::nonnegint) local s,i; option remember; if n<0 then RETURN(0) fi; if n=0 then RETURN(1) fi; s:=0; for i from 1 to b do s:=s+(-1)^(i-1)*(b-i+1)*A096261(n-i,b); od; end; seq(A096261(i,10),i=0..20);
  • Mathematica
    a[n_]:= a[n]= If[n<0, 0, If[n==0, 1, 10a[n-1] -9a[n-2] +8a[n-3] -7a[n-4] +6a[n-5] -5a[n-6] +4a[n-7] -3a[n-8] +2a[n-9] -a[n-10] ]]; Table[ a[n], {n,0,25}] (* Robert G. Wilson v, Aug 02 2004 *)
    LinearRecurrence[{10,-9,8,-7,6,-5,4,-3,2,-1}, {1,10,91,828,7534,68552,623756, 5675568,51642104,469892512}, 30] (* Harvey P. Dale, Dec 16 2013 *)
  • Sage
    def A096261_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P( 1/(1-10*x+9*x^2-8*x^3+7*x^4-6*x^5+5*x^6-4*x^7+3*x^8-2*x^9+x^10) ).list()
    A096261_list(30) # G. C. Greubel, Apr 17 2021

Formula

a(n) = 10*a(n-1) - 9*a(n-2) + 8*a(n-3) - 7*a(n-4) + 6*a(n-5) - 5*a(n-6) + 4*a(n-7) - 3*a(n-8) + 2*a(n-9) - 1*a(n-10), a(0)=1, a(n)=0, for n<0.
G.f.: 1/(1 - 10*x + 9*x^2 - 8*x^3 + 7*x^4 - 6*x^5 + 5*x^6 - 4*x^7 + 3*x^8 - 2*x^9 + x^10). - Colin Barker, Dec 06 2012

Extensions

More terms from Robert G. Wilson v, Aug 02 2004

A127895 Riordan array (1/(1+x)^3, x/(1+x)^3).

Original entry on oeis.org

1, -3, 1, 6, -6, 1, -10, 21, -9, 1, 15, -56, 45, -12, 1, -21, 126, -165, 78, -15, 1, 28, -252, 495, -364, 120, -18, 1, -36, 462, -1287, 1365, -680, 171, -21, 1, 45, -792, 3003, -4368, 3060, -1140, 231, -24, 1, -55, 1287, -6435, 12376, -11628, 5985, -1771, 300, -27, 1
Offset: 0

Views

Author

Paul Barry, Feb 04 2007

Keywords

Comments

The matrix inverse of the convolution triangle of A001764 (number of ternary trees). - Peter Luschny, Oct 09 2022

Examples

			Triangle begins
    1;
   -3,     1;
    6,    -6,     1;
  -10,    21,    -9,      1;
   15,   -56,    45,    -12,      1;
  -21,   126,  -165,     78,    -15,      1;
   28,  -252,   495,   -364,    120,    -18,     1;
  -36,   462, -1287,   1365,   -680,    171,   -21,     1;
   45,  -792,  3003,  -4368,   3060,  -1140,   231,   -24,   1;
  -55,  1287, -6435,  12376, -11628,   5985, -1771,   300, -27,   1;
   66, -2002, 12870, -31824,  38760, -26334, 10626, -2600, 378, -30, 1;
		

Crossrefs

Inverse is A127898.
Alternating sign version of A127893.

Programs

  • Magma
    [(-1)^(n-k)*Binomial(n+2*k+2, n-k): k in [0..n], n in [0..10]]; // G. C. Greubel, Apr 29 2018
    
  • Maple
    # Uses function InvPMatrix from A357585. Adds column 1, 0, 0, ... to the left.
    InvPMatrix(10, n -> binomial(3*n, n)/(2*n+1)); # Peter Luschny, Oct 09 2022
  • Mathematica
    Table[(-1)^(n-k)*Binomial[n+2*k+2, n-k], {n,0,10}, {k,0,n}]//Flatten (* G. C. Greubel, Apr 29 2018 *)
  • PARI
    for(n=0, 10, for(k=0,n, print1((-1)^(n-k)*binomial(n+2*k+2, n-k), ", "))) \\ G. C. Greubel, Apr 29 2018
    
  • Sage
    flatten([[(-1)^(n-k)*binomial(n+2*k+2, n-k) for k in (0..n)] for n in (0..12)]) # G. C. Greubel, Apr 16 2021

Formula

T(n, k) = (-1)^(n-k)*binomial(n +2*k +2, n-k).
Sum_{k=0..n} T(n, k) = A127896(n) (row sums).
Sum_{k=0..floor(n/2)} T(n-k, k) = (-1)^n*A095263(n) (diagonal sums).

Extensions

Terms a(50) onward added by G. C. Greubel, Apr 29 2018
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