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 20 results.

A049375 A convolution triangle of numbers obtained from A034687.

Original entry on oeis.org

1, 15, 1, 275, 30, 1, 5500, 775, 45, 1, 115500, 19250, 1500, 60, 1, 2502500, 471625, 44625, 2450, 75, 1, 55412500, 11495000, 1254000, 85000, 3625, 90, 1, 1246781250, 279675000, 34093125, 2698875, 143750, 5025, 105, 1, 28398906250, 6802812500
Offset: 1

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Author

Keywords

Comments

a(n,1) = A034687(n). a(n,m)=: s2(6; n,m), a member of a sequence of unsigned triangles including s2(2; n,m)= A007318(n-1,m-1) (Pascal's triangle). s2(3; n,m)= A035324(n,m), s2(4; n,m)= A035529(n,m), s2(5; n,m)= A048882(n,m).

Examples

			{1}; {15,1}; {275,30,1}; {5500,775,45,1}; ...
		

Crossrefs

Cf. A039746.

Programs

  • Mathematica
    a[n_, m_] := Coefficient[Series[((-1 + (1 - 25*x)^(-1/5))/5)^m, {x, 0, n}], x^n];
    Flatten[Table[a[n, m], {n, 1, 9}, {m, 1, n}]][[1 ;; 38]]
    (* Jean-François Alcover, Jun 21 2011, after g.f. *)

Formula

a(n, m) = 5*(5*(n-1)+m)*a(n-1, m)/n + m*a(n-1, m-1)/n, n >= m >= 1; a(n, m) := 0, n
G.f. for m-th column: ((-1+(1-25*x)^(-1/5))/5)^m.

A132057 A convolution triangle of numbers obtained from A034904.

Original entry on oeis.org

1, 28, 1, 980, 56, 1, 37730, 2744, 84, 1, 1531838, 130340, 5292, 112, 1, 64337196, 6136956, 299782, 8624, 140, 1, 2766499428, 288408120, 16120314, 568008, 12740, 168, 1, 121034349975, 13561837212, 841627332, 34401528, 956970, 17640, 196, 1
Offset: 1

Author

Wolfdieter Lang Sep 14 2007

Keywords

Comments

a(n,1) = A034904(n). a(n,m)=: s2(8; n,m), a member of a sequence of unsigned triangles including s2(2; n,m)=A007318(n-1,m-1) (Pascal's triangle). s2(3;n,m)= A035324(n,m), s2(4; n,m)= A035529(n,m), s2(5; n,m)= A048882(n,m), s2(6; n,m)= A049375; s2(7; n,m)=A092083.

Examples

			{1}; {28,1}; {980,56,1}; (37730,2744,84,1);...
		

Crossrefs

Cf. A132058 (row sums), A132059 (negative of alternating row sums).

Programs

  • Mathematica
    a[n_, m_] := a[n, m] = 7*(7*(n-1) + m)*a[n-1, m]/n + m*a[n-1, m-1]/n;
    a[n_, m_] /; n < m = 0; a[_, 0] = 0; a[1, 1] = 1;
    Flatten[Table[a[n, m], {n, 1, 8}, {m, 1, n}]][[1 ;; 36]]
    (* Jean-François Alcover, Jun 17 2011 *)

Formula

a(n, m) = 7*(7*(n-1)+m)*a(n-1, m)/n + m*a(n-1, m-1)/n, n >= m >= 1; a(n, m) := 0, n
G.f. for m-th column: ((-1+(1-49*x)^(-1/7))/7)^m.

A035330 5-fold convolution of A001700(n), n >= 0.

Original entry on oeis.org

1, 15, 140, 1045, 6835, 40963, 230720, 1240740, 6437890, 32468470, 160010280, 773624615, 3680728375, 17274086235, 80119845080, 367821324040, 1673528845710, 7554110698850, 33858536700040, 150802994850570
Offset: 0

Keywords

Comments

Fifth column of triangular array A035324.

Crossrefs

Programs

  • Mathematica
    Array[(#^2 + 27 # + 122) Binomial[2 (# + 5), # + 5]/24 - 5 (# + 8)*2^(2 # + 5) &, 20, 0] (* Michael De Vlieger, Sep 04 2018 *)

Formula

a(n) = (n^2+27*n+122)*binomial(2*(n+5), n+5)/24 - 5*(n+8)*2^(2*n+5) = A035324(n+5, 5);
G.f.: c(x)^5/(1-4*x)^(5/2), where c(x) = g.f. for Catalan numbers A000108.

A134283 A certain partition array in Abramowitz-Stegun (A-St)order, called M_0(3).

Original entry on oeis.org

1, 3, 1, 10, 6, 1, 35, 20, 9, 9, 1, 126, 70, 60, 30, 27, 12, 1, 462, 252, 210, 100, 105, 180, 27, 40, 54, 15, 1, 1716, 924, 756, 700, 378, 630, 300, 270, 140, 360, 108, 50, 90, 18, 1, 6435, 3432, 2772, 2520, 1225, 1386, 2268, 2100, 945, 900, 504, 1260, 600, 1080, 81
Offset: 1

Author

Wolfdieter Lang, Nov 13 2007

Keywords

Comments

For the A-St order of partitions see the Abramowitz-Stegun reference given in A117506.
Partition number array M_0(3); the k=3 member in the family of a generalization of the multinomial number arrays M_0 = M_0(2) = A048996.
The sequence of row lengths is A000041 (partition numbers) [1, 2, 3, 5, 7, 11, 15, 22, 30, 42, ...].
The s2(3,n,m):=A035324(n,m) numbers (generalized Pascal triangle) are obtained by summing in row n all numbers with the same part number m. In the same manner the s2(2,n,m) = binomial(n-1,m-1) = A007318(n-1,m-1) numbers are obtained from the partition array M_0 = A048996.

Examples

			[1]; [3,1]; [10,6,1]; [35,20,9,9,1]; [126,70,60,30,27,12,1]; ...
		

Crossrefs

Cf. A049027 (row sums, also of triangle A035324).

Formula

a(n,k) = m!*Product_{j=1..n} (s2(3,j,1)^e(n,k,j))/e(n,k,j)! with s2(3,n,1) = A035324(n,1) = A001700(n-1) and the exponent e(n,k,j) of j in the k-th partition of n in the A-St ordering of the partitions of n. Exponents 0 can be omitted due to 0!=1.

A171488 Riordan array (f(x), x*f(x)) where f(x) is the g.f. of A005773(n+1)= 1,2,5,13,35,96,267,...

Original entry on oeis.org

1, 2, 1, 5, 4, 1, 13, 14, 6, 1, 35, 46, 27, 8, 1, 96, 147, 107, 44, 10, 1, 267, 462, 396, 204, 65, 12, 1, 750, 1437, 1404, 858, 345, 90, 14, 1, 2123, 4438, 4835, 3388, 1625, 538, 119, 16, 1, 6046, 13637, 16305, 12802, 7072, 2805, 791, 152, 18, 1
Offset: 0

Author

Philippe Deléham, Dec 10 2009

Keywords

Comments

Equal to A064189*B = B*A054336 = B^(-1)*A035324, B = A007318.

Examples

			Triangle T(n,k) (0<=k<=n) begins:
   1;
   2,   1;
   5,   4,   1;
  13,  14,   6,  1;
  35,  46,  27,  8,  1;
  96, 147, 107, 44, 10, 1;
  ...
		

Crossrefs

Programs

  • Maxima
    T(n,k)=((k+1)*sum(binomial(2*j+k,j)*(-1)^j*3^(n-j-k)*binomial(n+1,j+k+1),j,0,n-k))/(n+1); /* Vladimir Kruchinin Sep 30 2020 */

Formula

Sum_{k, 0<=k<=n} T(n,k)*x^k = A005043(n), A001006(n), A005773(n+1), A059738(n) for x = -2, -1, 0, 1 respectively.
T(n,k) = T(n-1,k-1) + 2*T(n-1,k) + sum_{i, i>=0} T(n-1,k+1+i)*(-1)^i. - Philippe Deléham, Feb 23 2012
T(n,k) = (k+1)*Sum_{j=0..n-k} C(2*j+k,j)*(-1)^j*3^(n-j-k)*C(n+1,j+k+1)/(n+1). - Vladimir Kruchinin Sep 30 2020

A134284 A certain partition array in Abramowitz-Stegun order (A-St order), called M_0(3)/M_0.

Original entry on oeis.org

1, 3, 1, 10, 3, 1, 35, 10, 9, 3, 1, 126, 35, 30, 10, 9, 3, 1, 462, 126, 105, 100, 35, 30, 27, 10, 9, 3, 1, 1716, 462, 378, 350, 126, 105, 100, 90, 35, 30, 27, 10, 9, 3, 1, 6435, 1716, 1386, 1260, 1225, 462, 378, 350, 315, 300, 126, 105, 100, 90, 81, 35, 30, 27, 10, 9, 3, 1
Offset: 1

Author

Wolfdieter Lang, Nov 13 2007

Keywords

Comments

The sequence of row lengths is A000041 (partition numbers) [1, 2, 3, 5, 7, 11, 15, 22, 30, 42, ...].
For the A-St order of partitions see the Abramowitz-Stegun reference given in A117506.
Partition number array M_0(3)= A134283 with each entry divided by the corresponding one of the partition number array M_0 = M_0(2) = A048996; in short M_0(3)/M_0.

Examples

			[1]; [3,1]; [10,3,1]; [35,10,9,3,1]; [126,35,30,10,9,3,1]; ...
a(4,3) = 9 = 3^2 because (2^2) is the k=4 partition of n=4 in A-St order and s2(3,2,1)=3.
		

Crossrefs

Cf. A134826 (row sums coinciding with those of triangle A134285).

Formula

a(n,k) = Product_{j=1..n} s2(3,j,1)^e(n,k,j) with s2(3,n,1) = A035324(n,1) = A001700(n-1) = binomial(2*n-1,n) and with the exponent e(n,k,j) of j in the k-th partition of n in the A-St ordering of the partitions of n.
a(n,k) = A134283(n,k)/A048996(n,k) (division of partition arrays M_0(3) by M_0).

A154930 Inverse of Fibonacci convolution array A154929.

Original entry on oeis.org

1, -2, 1, 5, -4, 1, -15, 14, -6, 1, 51, -50, 27, -8, 1, -188, 187, -113, 44, -10, 1, 731, -730, 468, -212, 65, -12, 1, -2950, 2949, -1956, 970, -355, 90, -14, 1, 12235, -12234, 8291, -4356, 1785, -550, 119, -16, 1, -51822, 51821, -35643, 19474, -8612, 3021
Offset: 0

Author

Paul Barry, Jan 17 2009

Keywords

Comments

Alternating sign version of A104259. Row sums are (-1)^n*A033321. First column is (-1)^n*A007317.

Examples

			Triangle begins
1,
-2, 1,
5, -4, 1,
-15, 14, -6, 1,
51, -50, 27, -8, 1,
-188, 187, -113, 44, -10, 1,
731, -730, 468, -212, 65, -12, 1,
-2950, 2949, -1956, 970, -355, 90, -14, 1
Production array is
-2, 1,
1, -2, 1,
-1, 1, -2, 1,
1, -1, 1, -2, 1,
-1, 1, -1, 1, -2, 1,
1, -1, 1, -1, 1, -2, 1,
-1, 1, -1, 1, -1, 1, -2, 1
or ((1-x-x^2)/(1+x),x) beheaded.
		

Crossrefs

Formula

Riordan array ((1/(1+x))c(-x/(1+x)), (x/(1+x))c(x/(1+x))), c(x) the g.f. of A000108;
Riordan array ((sqrt(1+6x+5x^2)-x-1)/(2x(1+x)),(sqrt(1+6x+5x^2)-x-1)/ (2(1+x)));
Triangle T(n,k) = sum{j=0..n, (-1)^(n-k)*C(n,j)*C(2j-k,j-k)(k+1)/(j+1)}.
T(n,k) = T(n-1,k-1) -2*T(n-1,k) + Sum_{i, i>=0} T(n-1,k+1+i)*(-1)^i. - Philippe Deléham, Feb 23 2012

A116396 Expansion of 2/((2+x)*sqrt(1-4*x)-x).

Original entry on oeis.org

1, 2, 7, 25, 93, 353, 1358, 5273, 20614, 81003, 319584, 1264924, 5019743, 19963699, 79541181, 317406302, 1268283199, 5073605801, 20316709251, 81427911966, 326612013623, 1310968893954, 5265285993860, 21158914176719, 85071253608611
Offset: 0

Author

Paul Barry, Feb 12 2006

Keywords

Comments

Diagonal sums of number triangle A116395.
Diagonal sums of the Riordan matrix ((1-sqrt(1-4*x))/(2*x*sqrt(1-4*x)),(1-sqrt(1-4*x))/(2*sqrt(1-4*x))) (A035324). - Emanuele Munarini, Apr 26 2011

Programs

  • Mathematica
    CoefficientList[Series[(x+(2+x)Sqrt[1-4x])/(2-6x-8x^2-2x^3),{x,0,25}],x] (* Emanuele Munarini, Apr 26 2011 *)

Formula

a(n) = Sum_{k=0..floor(n/2)} (4^(n-k)/2^k)*Sum_{j=0..k} C(k,j)*C(n-k+(j-1)/2,n-k)*(-1)^(k-j).
D-finite with recurrence: +2*n*a(n) +(-13*n+10)*a(n-1) +(9*n-16)*a(n-2) +2*(19*n-41)*a(n-3) +(23*n-66)*a(n-4) +2*(2*n-7)*a(n-5)=0. - R. J. Mathar, Jan 24 2020

A188110 Triangle T(n,m), [x*A(x)]^m=sum(n>=m T(n,m)*x^n), where A(x) satisfies x*A(x)^3= -(2*x*A(x)^2+sqrt(1-4*x*A(x)^2)-1)/(4*x*A(x)^2+sqrt(1-4*x*A(x)^2)-1).

Original entry on oeis.org

1, 3, 1, 28, 6, 1, 350, 65, 9, 1, 5020, 868, 111, 12, 1, 78023, 12924, 1581, 166, 15, 1, 1278340, 205766, 24468, 2516, 230, 18, 1, 21740636, 3428438, 399735, 40489, 3700, 303, 21, 1, 380161308, 59034600, 6784186, 679460, 61905, 5160, 385, 24, 1, 6792111260, 1042169972, 118444293, 11759612, 1067738, 89715, 6923, 476, 27, 1
Offset: 1

Author

Vladimir Kruchinin, Mar 21 2011

Keywords

Crossrefs

Cf. A035324.

Programs

  • Mathematica
    (* S = A035324 *)
    S[n_, m_] /; n >= m >= 1 := S[n, m] = 2(2(n-1) + m)(S[n - 1, m]/n) + m (S[n - 1, m - 1]/n); S[n_, m_] /; n < m = 0; S[n_, 0] = 0; S[1, 1] = 1;
    T[n_, m_] := m/(2n-m) S[3n - 2m, 2n - m];
    Table[T[n, m], {n, 1, 10}, {m, 1, n}] // Flatten (* Jean-François Alcover, Feb 16 2019 *)

Formula

T(n,m) = m/(2*n-m)*A035324(3*n-2*m,2*n-m).

A188109 Triangle T(n,m), [x*A(x)]^m=sum(n>=m T(n,m)*x^n), where A(x) satisfies x*A(x)^2= -(2*x*A(x)+sqrt(1-4*x*A(x))-1)/(4*x*A(x)+sqrt(1-4*x*A(x))-1).

Original entry on oeis.org

1, 3, 1, 19, 6, 1, 152, 47, 9, 1, 1367, 418, 84, 12, 1, 13195, 4007, 825, 130, 15, 1, 133556, 40368, 8433, 1400, 185, 18, 1, 1398696, 421332, 88872, 15239, 2170, 249, 21, 1, 15029311, 4515706, 959080, 168112, 25100, 3162, 322, 24, 1, 164764985, 49405895, 10547361, 1878462, 289788, 38772, 4403, 404, 27, 1
Offset: 1

Author

Vladimir Kruchinin, Mar 21 2011

Keywords

Examples

			1;
3, 1;
19, 6, 1;
152, 47, 9, 1;
1367, 418, 84, 12, 1;
13195, 4007, 825, 130, 15, 1;
133556, 40368, 8433, 1400, 185, 18, 1;
1398696, 421332, 88872, 15239, 2170, 249, 21, 1
		

Crossrefs

Programs

  • Mathematica
    (* S = A035324 *)
    S[n_, m_] /; n >= m >= 1 := S[n, m] = 2(2(n-1)+m)(S[n-1, m]/n) + m(S[n-1, m-1]/n); S[n_, m_] /; n < m = 0; S[n_, 0] = 0; S[1, 1] = 1;
    T[n_, m_] := m/n S[2n-m, n];
    Table[T[n, m], {n, 1, 10}, {m, 1, n}] // Flatten (* Jean-François Alcover, Feb 16 2019 *)

Formula

T(n,m) = m/n*A035324(2*n-m,n).
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