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.

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A193897 Triangular array: the self-fusion of (p(n,x)), where p(n,x)=sum{(k+1)*x^k : 0<=k<=n}.

Original entry on oeis.org

1, 2, 1, 3, 6, 3, 4, 9, 12, 6, 5, 12, 18, 20, 10, 6, 15, 24, 30, 30, 15, 7, 18, 30, 40, 45, 42, 21, 8, 21, 36, 50, 60, 63, 56, 28, 9, 24, 42, 60, 75, 84, 84, 72, 36, 10, 27, 48, 70, 90, 105, 112, 108, 90, 45, 11, 30, 54, 80, 105, 126, 140, 144, 135, 110, 55, 12, 33
Offset: 0

Views

Author

Clark Kimberling, Aug 08 2011

Keywords

Comments

See A193722 for the definition of fusion of two sequences of polynomials or triangular arrays.

Examples

			First six rows of A193897:
1
2...1
3...6....3
4...9....12...6
5...12...18...20...10
6...15...24...30...30...15
		

Crossrefs

Programs

  • Mathematica
    z = 12;
    p[n_, x_] := (n + 1)*x^n + p[n - 1, x] (* #7 *); p[0, x_] := 1;
    q[n_, x_] := p[n, x];
    t[n_, k_] := Coefficient[p[n, x], x^k]; t[n_, 0] := p[n, x] /. x -> 0;
    w[n_, x_] := Sum[t[n, k]*q[n + 1 - k, x], {k, 0, n}]; w[-1, x_] := 1
    g[n_] := CoefficientList[w[n, x], {x}]
    TableForm[Table[Reverse[g[n]], {n, -1, z}]]
    Flatten[Table[Reverse[g[n]], {n, -1, z}]]  (* A193897 *)
    TableForm[Table[g[n], {n, -1, z}]]
    Flatten[Table[g[n], {n, -1, z}]]  (* A193898 *)

A193917 Triangular array: the self-fusion of (p(n,x)), where p(n,x)=sum{F(k+1)*x^(n-k) : 0<=k<=n}, where F=A000045 (Fibonacci numbers).

Original entry on oeis.org

1, 1, 1, 1, 2, 3, 2, 3, 6, 9, 3, 5, 9, 15, 24, 5, 8, 15, 24, 40, 64, 8, 13, 24, 39, 64, 104, 168, 13, 21, 39, 63, 104, 168, 273, 441, 21, 34, 63, 102, 168, 272, 441, 714, 1155, 34, 55, 102, 165, 272, 440, 714, 1155, 1870, 3025, 55, 89, 165, 267, 440, 712, 1155
Offset: 0

Views

Author

Clark Kimberling, Aug 09 2011

Keywords

Comments

See A193722 for the definition of fusion of two sequences of polynomials or triangular arrays. (Fusion is defined at A193822; fission, at A193742; see A202503 and A202453 for infinite-matrix representations of fusion and fission.)
First five rows of P (triangle of coefficients of polynomials p(n,x)):
1
1...1
1...1...2
1...1...2...3
1...1...2...3...5
First eight rows of A193917:
1
1...1
1...2...3
2...3...6...9
3...5...9...15...24
5...8...15..24...40...64
8...13..24..39...64...104..168
13..21..39..63...104..168..273..441
...
col 1: A000045
col 2: A000045
col 3: A022086
col 4: A022086
col 5: A022091
col 6: A022091
col 7: A022355
col 8: A022355
right edge, w(n,n): A064831
w(n,n-1): A001654
w(n,n-2): A064831
w(n,n-3): A059840
w(n,n-4): A080097
w(n,n-5): A080143
w(n,n-6): A080144
Suppose n is an even positive integer and w(n+1,x) is the polynomial matched to row n+1 of A193917 as in the Mathematica program (and definition of fusion at A193722), where the first row is counted as row 0.

Examples

			First six rows:
1
1...1
1...2...3
2...3...6....9
3...5...9....15...24
5...8...15...24...40...64
		

Crossrefs

Programs

  • Mathematica
    z = 12;
    p[n_, x_] := Sum[Fibonacci[k + 1]*x^(n - k), {k, 0, n}];
    q[n_, x_] := p[n, x];
    t[n_, k_] := Coefficient[p[n, x], x^k]; t[n_, 0] := p[n, x] /. x -> 0;
    w[n_, x_] := Sum[t[n, k]*q[n + 1 - k, x], {k, 0, n}]; w[-1, x_] := 1
    g[n_] := CoefficientList[w[n, x], {x}]
    TableForm[Table[Reverse[g[n]], {n, -1, z}]]
    Flatten[Table[Reverse[g[n]], {n, -1, z}]]  (* A193917 *)
    TableForm[Table[g[n], {n, -1, z}]]
    Flatten[Table[g[n], {n, -1, z}]]  (* A193918 *)

A193949 Triangular array: the fusion of (p(n,x)) by (q(n,x)), where p(n,x)=sum{F(k+1)*x^(n-k) : 0<=k<=n}, where F=A000045 (Fibonacci numbers), and q(n,x)=sum{(k+1)(n+1)*x^(n-k) : 0<=k<=n}.

Original entry on oeis.org

1, 2, 4, 3, 8, 13, 8, 19, 32, 45, 15, 38, 64, 92, 120, 30, 75, 128, 184, 242, 300, 56, 142, 243, 352, 464, 578, 692, 104, 264, 454, 659, 872, 1088, 1306, 1524, 189, 482, 831, 1210, 1604, 2006, 2411, 2818, 3225, 340, 869, 1502, 2191, 2910, 3644, 4386
Offset: 0

Views

Author

Clark Kimberling, Aug 10 2011

Keywords

Comments

See A193722 for the definition of fusion of two sequences of polynomials or triangular arrays.

Examples

			First six rows:
1
2....4
3....8....13
8....19...32...45
15...38...64...92...120
30...75...128..184..242..300
		

Crossrefs

Programs

  • Mathematica
    z = 12;
    p[n_, x_] := Sum[Fibonacci[k + 1]*x^(n - k), {k, 0, n}];
    q[n_, x_] := Sum[(k + 1) (n + 1)*x^(n - k), {k, 0, n}];
    t[n_, k_] := Coefficient[p[n, x], x^k]; t[n_, 0] := p[n, x] /. x -> 0;
    w[n_, x_] := Sum[t[n, k]*q[n + 1 - k, x], {k, 0, n}]; w[-1, x_] := 1
    g[n_] := CoefficientList[w[n, x], {x}]
    TableForm[Table[Reverse[g[n]], {n, -1, z}]]
    Flatten[Table[Reverse[g[n]], {n, -1, z}]]  (* A193949 *)
    TableForm[Table[g[n], {n, -1, z}]]
    Flatten[Table[g[n], {n, -1, z}]]  (* A193950 *)

A193955 Triangular array: the fusion of (p(n,x)) by (q(n,x)), where p(n,x)=sum{F(k+1)*x^(n-k) : 0<=k<=n}, where F=A000045 (Fibonacci numbers), and q(n,x)=sum{((k+1)^2)*x^(n-k) : 0<=k<=n}.

Original entry on oeis.org

1, 1, 4, 1, 5, 13, 2, 9, 23, 45, 3, 14, 36, 71, 120, 5, 23, 59, 116, 196, 300, 8, 37, 95, 187, 316, 484, 692, 13, 60, 154, 303, 512, 784, 1121, 1524, 21, 97, 249, 490, 828, 1268, 1813, 2465, 3225, 34, 157, 403, 793, 1340, 2052, 2934, 3989, 5219, 6625, 55
Offset: 0

Views

Author

Clark Kimberling, Aug 10 2011

Keywords

Comments

See A193722 for the definition of fusion of two sequences of polynomials or triangular arrays.

Examples

			First six rows:
1
1...4
1...5....13
2...9....23...45
3...14...36...71....120
5...23...59...116...196...300
		

Crossrefs

Programs

  • Mathematica
    z = 12;
    p[n_, x_] := Sum[Fibonacci[k + 1]*x^(n - k), {k, 0, n}];
    q[n_, x_] := Sum[((k + 1)^2)*x^(n - k), {k, 0, n}] ;
    t[n_, k_] := Coefficient[p[n, x], x^k]; t[n_, 0] := p[n, x] /. x -> 0;
    w[n_, x_] := Sum[t[n, k]*q[n + 1 - k, x], {k, 0, n}]; w[-1, x_] := 1
    g[n_] := CoefficientList[w[n, x], {x}]
    TableForm[Table[Reverse[g[n]], {n, -1, z}]]
    Flatten[Table[Reverse[g[n]], {n, -1, z}]]  (* A193955 *)
    TableForm[Table[g[n], {n, -1, z}]]
    Flatten[Table[g[n], {n, -1, z}]]  (* A193956 *)

A196665 Expansion of g.f. (1-6*x)/(1-19*x).

Original entry on oeis.org

1, 13, 247, 4693, 89167, 1694173, 32189287, 611596453, 11620332607, 220786319533, 4194940071127, 79703861351413, 1514373365676847, 28773093947860093, 546688785009341767, 10387086915177493573, 197354651388372377887, 3749738376379075179853
Offset: 0

Views

Author

Philippe Deléham, Oct 05 2011

Keywords

Crossrefs

Formula

a(0) = 1, a(n) = 13*19^(n-1) for n>0.
a(n) = Sum_{k=0..n} A193722(n,k)*6^k.
From Elmo R. Oliveira, Mar 18 2025: (Start)
E.g.f.: (13*exp(19*x) + 6)/19.
a(n) = 19*a(n-1) for n > 1. (End)

A202674 Symmetric matrix based on (1,3,5,7,9,...), by antidiagonals.

Original entry on oeis.org

1, 3, 3, 5, 10, 5, 7, 18, 18, 7, 9, 26, 35, 26, 9, 11, 34, 53, 53, 34, 11, 13, 42, 71, 84, 71, 42, 13, 15, 50, 89, 116, 116, 89, 50, 15, 17, 58, 107, 148, 165, 148, 107, 58, 17, 19, 66, 125, 180, 215, 215, 180, 125, 66, 19, 21, 74, 143, 212, 265, 286, 265, 212
Offset: 1

Views

Author

Clark Kimberling, Dec 22 2011

Keywords

Comments

Let s=(1,3,5,7,9,...) and let T be the infinite square matrix whose n-th row is formed by putting n-1 zeros before the terms of s. Let T' be the transpose of T. Then A202674 represents the matrix product M=T'*T. M is the self-fusion matrix of s, as defined at A193722. See A202675 for characteristic polynomials of principal submatrices of M.
...
row 1 (1,3,5,7,...) A005408
diagonal (1,10,35,84,...) A000447
antidiagonal sums (1,6,20,50,...) A002415

Examples

			Northwest corner:
1....3....5.....7.....9
3...10...18....26....34
5...18...35....53....71
7...26...53....84...116
9...34...71...116...165
		

Crossrefs

Programs

  • Mathematica
    U = NestList[Most[Prepend[#, 0]] &, #, Length[#] - 1] &[Table[2 k - 1, {k, 1, 15}]];
    L = Transpose[U]; M = L.U; TableForm[M]
    m[i_, j_] := M[[i]][[j]];
    Flatten[Table[m[i, n + 1 - i], {n, 1, 12}, {i, 1, n}]]

A202676 Symmetric matrix based on (1,4,7,10,13,...), by antidiagonals.

Original entry on oeis.org

1, 4, 4, 7, 17, 7, 10, 32, 32, 10, 13, 47, 66, 47, 13, 16, 62, 102, 102, 62, 16, 19, 77, 138, 166, 138, 77, 19, 22, 92, 174, 232, 232, 174, 92, 22, 25, 107, 210, 298, 335, 298, 210, 107, 25, 28, 122, 246, 364, 440, 440, 364, 246, 122, 28, 31, 137, 282, 430
Offset: 1

Views

Author

Clark Kimberling, Dec 22 2011

Keywords

Comments

Let s=(1,4,7,10,13,...) and let T be the infinite square matrix whose n-th row is formed by putting n-1 zeros before the terms of s. Let T' be the transpose of T. Then A202676 represents the matrix product M=T'*T. M is the self-fusion matrix of s, as defined at A193722. See A202677 for characteristic polynomials of principal submatrices of M.
...
row 1 (1,4,7,10,...) A016777
diagonal (1,17,66,166,...) A024215
...
Sum[m[i, n], {i, 1, n}] + Sum[m[n, j], {j, 1, n - 1}]: (1,25,144,484,..), the squares of the pentagonal numbers (A000326).

Examples

			Northwest corner:
1....4....7...10...13...16
4...17...32...47...62...77
7...32...66..102..138..174
10..47..102..166..232..298
13..62..138..232..335..440
		

Crossrefs

Cf. A202677.

Programs

  • Mathematica
    U = NestList[Most[Prepend[#, 0]] &, #, Length[#] - 1] &[Table[3 k - 2, {k, 1, 15}]];
    L = Transpose[U]; M = L.U; TableForm[M]
    m[i_, j_] := M[[i]][[j]];
    Flatten[Table[m[i, n + 1 - i], {n, 1, 12}, {i, 1, n}]]

A202869 Symmetric matrix based on the lower Wythoff sequence, A000201, by antidiagonals.

Original entry on oeis.org

1, 3, 3, 4, 10, 4, 6, 15, 15, 6, 8, 22, 26, 22, 8, 9, 30, 39, 39, 30, 9, 11, 35, 54, 62, 54, 35, 11, 12, 42, 66, 87, 87, 66, 42, 12, 14, 47, 79, 108, 126, 108, 79, 47, 14, 16, 54, 90, 132, 159, 159, 132, 90, 54, 16, 17, 62, 103, 151, 196, 207, 196, 151, 103, 62
Offset: 1

Views

Author

Clark Kimberling, Dec 26 2011

Keywords

Comments

Let s=(1,3,4,6,8,...)=A000201 and let T be the infinite square matrix whose n-th row is formed by putting n-1 zeros before the terms of s. Let T' be the transpose of T. Then A202869 represents the matrix product M=T'*T. M is the self-fusion matrix of s, as defined at A193722. See A202870 for characteristic polynomials of principal submatrices of M, with interlacing zeros.

Examples

			Northwest corner:
1...3....4....6....8....9
3...10...15...22...30...35
4...15...26...39...54...66
6...22...39...62...87...108
8...30...54...87...126..159
		

Crossrefs

Cf. A202870.

Programs

  • Mathematica
    s[k_] := Floor[k*GoldenRatio];
    U = NestList[Most[Prepend[#, 0]] &, #, Length[#] - 1] &[Table[s[k], {k, 1, 15}]];
    L = Transpose[U]; M = L.U; TableForm[M]
    m[i_, j_] := M[[i]][[j]];
    Flatten[Table[m[i, n + 1 - i], {n, 1, 12}, {i, 1, n}]]
    f[n_] := Sum[m[i, n], {i, 1, n}] + Sum[m[n, j], {j, 1, n - 1}]
    Table[f[n], {n, 1, 12}]
    Table[Sqrt[f[n]], {n, 1, 12}]   (* A054347 *)
    Table[m[1, j], {j, 1, 12}]        (* A000201 *)

A202871 Symmetric matrix based on the Lucas sequence, A000032, by antidiagonals.

Original entry on oeis.org

1, 3, 3, 4, 10, 4, 7, 15, 15, 7, 11, 25, 26, 25, 11, 18, 40, 43, 43, 40, 18, 29, 65, 69, 75, 69, 65, 29, 47, 105, 112, 120, 120, 112, 105, 47, 76, 170, 181, 195, 196, 195, 181, 170, 76, 123, 275, 293, 315, 318, 318, 315, 293, 275, 123, 199, 445, 474, 510, 514
Offset: 1

Views

Author

Clark Kimberling, Dec 26 2011

Keywords

Comments

Let s=(1,3,4,7,11,...)=A000201 and let T be the infinite square matrix whose n-th row is formed by putting n-1 zeros before the terms of s. Let T' be the transpose of T. Then A202871 represents the matrix product M=T'*T. M is the self-fusion matrix of s, as defined at A193722. See A202872 for characteristic polynomials of principal submatrices of M, with interlacing zeros.

Examples

			Northwest corner:
1....3....4....7....11...18
3....10...15...25...40...65
4....15...26...43...69...112
7....25...43...75...120..195
11...40...69...120..196..318
		

Crossrefs

Cf. A202872.

Programs

  • Mathematica
    s[k_] := LucasL[k];
    U = NestList[Most[Prepend[#, 0]] &, #, Length[#] - 1] &[Table[s[k], {k, 1, 15}]];
    L = Transpose[U]; M = L.U; TableForm[M]
    m[i_, j_] := M[[i]][[j]];
    Flatten[Table[m[i, n + 1 - i], {n, 1, 12}, {i, 1, n}]]
    f[n_] := Sum[m[i, n], {i, 1, n}] + Sum[m[n, j], {j, 1, n - 1}]
    Table[f[n], {n, 1, 12}]
    Table[Sqrt[f[n]], {n, 1, 12}] (* A027961 *)
    Table[m[1, j], {j, 1, 12}]    (* A000032 *)

A202873 Symmetric matrix based on (1,3,7,15,31,...), by antidiagonals.

Original entry on oeis.org

1, 3, 3, 7, 10, 7, 15, 24, 24, 15, 31, 52, 59, 52, 31, 63, 108, 129, 129, 108, 63, 127, 220, 269, 284, 269, 220, 127, 255, 444, 549, 594, 594, 549, 444, 255, 511, 892, 1109, 1214, 1245, 1214, 1109, 892, 511, 1023, 1788, 2229, 2454, 2547, 2547, 2454
Offset: 1

Views

Author

Clark Kimberling, Dec 26 2011

Keywords

Comments

Let s=(1,3,7,15,31,...) and let T be the infinite square matrix whose n-th row is formed by putting n-1 zeros before the terms of s. Let T' be the transpose of T. Then A202873 represents the matrix product M=T'*T. M is the self-fusion matrix of s, as defined at A193722. See A202767 for characteristic polynomials of principal submatrices of M.

Examples

			Northwest corner:
1.....3.....7...15...31.....63
3....10....24...52...108...220
7....24....59..129...269...549
15...52...129..284...594..1214
31...108..269..594..1245..2547
		

Crossrefs

Cf. A202767.

Programs

  • Mathematica
    s[k_] := -1 + 2^k;
    U = NestList[Most[Prepend[#, 0]] &, #, Length[#] - 1] &[Table[s[k], {k, 1, 15}]];
    L = Transpose[U]; M = L.U; TableForm[M]
    m[i_, j_] := M[[i]][[j]];
    Flatten[Table[m[i, n + 1 - i], {n, 1, 12}, {i, 1, n}]]
    f[n_] := Sum[m[i, n], {i, 1, n}] + Sum[m[n, j], {j, 1, n - 1}]
    Table[f[n], {n, 1, 12}]
    Table[Sqrt[f[n]], {n, 1, 12}] (* A000295, Eulerian *)
    Table[m[1, j], {j, 1, 12}]    (* A000225 *)
    Table[m[2, j], {j, 1, 12}]    (* A053208 *)
Previous Showing 41-50 of 92 results. Next