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.

Showing 1-10 of 10 results.

A010741 Shifts 3 places left under inverse binomial transform.

Original entry on oeis.org

1, 2, 4, 1, 1, 1, -6, 14, -25, 32, 6, -250, 1222, -4380, 13059, -31705, 48464, 76354, -1159911, 7041015, -33400183, 135931668, -473704510, 1277600695, -1233828142, -16196871172, 169736941512, -1156974034428, 6577630531262, -32839667759307, 142900400342885
Offset: 0

Views

Author

Keywords

Crossrefs

Programs

  • Maple
    a:= proc(n) option remember; (m-> `if`(m<0, 2^n,
          add(a(m-j)*binomial(m, j)*(-1)^j, j=0..m)))(n-3)
        end:
    seq(a(n), n=0..35);  # Alois P. Heinz, Feb 02 2022
  • Mathematica
    a[n_] := a[n] = With[{m = n - 3}, If[m < 0, 2^n,
         Sum[a[m - j]*Binomial[m, j]*(-1)^j, {j, 0, m}]]];
    Table[a[n], {n, 0, 35}] (* Jean-François Alcover, Mar 02 2022, after Alois P. Heinz *)

Formula

G.f. A(x) satisfies: A(x) = 1 + 2*x + 4*x^2 + x^3*A(x/(1 + x))/(1 + x). - Ilya Gutkovskiy, Feb 02 2022

A010743 Shifts 4 places left under inverse binomial transform.

Original entry on oeis.org

1, 2, 4, 8, 1, 1, 1, 1, -14, 45, -101, 189, -331, 668, -1932, 7206, -27779, 101365, -347439, 1139851, -3690766, 12258863, -43341845, 166059261, -682516519, 2930522990, -12823188092, 56366526324, -247898684759, 1094571175769, -4890163717903, 22310147976797
Offset: 0

Views

Author

Keywords

Crossrefs

Programs

  • Maple
    a:= proc(n) option remember; (m-> `if`(m<0, 2^n,
          add(a(m-j)*binomial(m, j)*(-1)^j, j=0..m)))(n-4)
        end:
    seq(a(n), n=0..35);  # Alois P. Heinz, Feb 02 2022
  • Mathematica
    a[n_] := a[n] = Function[m, If[m < 0, 2^n, Sum[a[m - j]* Binomial[m, j]*(-1)^j, {j, 0, m}]]][n - 4];
    Table[a[n], {n, 0, 35}] (* Jean-François Alcover, Mar 08 2023, after Alois P. Heinz *)

Formula

G.f. A(x) satisfies: A(x) = 1 + 2*x + 4*x^2 + 8*x^3 + x^4*A(x/(1 + x))/(1 + x). - Ilya Gutkovskiy, Feb 02 2022

A010745 Shifts 5 places left under inverse binomial transform.

Original entry on oeis.org

1, 2, 4, 8, 16, 1, 1, 1, 1, 1, -30, 124, -336, 734, -1401, 2404, -3485, 2212, 14630, -105408, 497131, -1995782, 7265342, -24576128, 77966104, -231218343, 626012198, -1430352680, 1894959964, 6114950887, -73791743479, 472896657475, -2523776826105, 12272646042530
Offset: 0

Views

Author

Keywords

Crossrefs

Programs

  • Maple
    a:= proc(n) option remember; (m-> `if`(m<0, 2^n,
          add(a(m-j)*binomial(m, j)*(-1)^j, j=0..m)))(n-5)
        end:
    seq(a(n), n=0..35);  # Alois P. Heinz, Feb 02 2022
  • Mathematica
    a[n_] := a[n] = Function[m, If[m < 0, 2^n, Sum[a[m-j]*Binomial[m, j]*(-1)^j, {j, 0, m}]]][n-5]; Table[a[n], {n, 0, 35}] (* Jean-François Alcover, Jan 13 2025, after Alois P. Heinz *)

Formula

G.f. A(x) satisfies: A(x) = 1 + 2*x + 4*x^2 + 8*x^3 + 16*x^4 + x^5*A(x/(1 + x))/(1 + x). - Ilya Gutkovskiy, Feb 02 2022

A010747 Shifts 6 places left under inverse binomial transform.

Original entry on oeis.org

1, 2, 4, 8, 16, 32, 1, 1, 1, 1, 1, 1, -62, 315, -1002, 2505, -5377, 10373, -18544, 32086, -60468, 154687, -567986, 2422043, -10225382, 40740231, -152497274, 539809668, -1822828757, 5928049329, -18782176673, 58918636670, -187382010256, 623524250516
Offset: 0

Views

Author

Keywords

Crossrefs

Programs

  • Maple
    a:= proc(n) option remember; (m-> `if`(m<0, 2^n,
          add(a(m-j)*binomial(m, j)*(-1)^j, j=0..m)))(n-6)
        end:
    seq(a(n), n=0..35);  # Alois P. Heinz, Feb 02 2022
  • Mathematica
    a[n_] := a[n] = Function[m, If[m < 0, 2^n, Sum[a[m - j]* Binomial[m, j]*(-1)^j, {j, 0, m}]]][n - 6];
    Table[a[n], {n, 0, 35}] (* Jean-François Alcover, Mar 08 2023, after Alois P. Heinz *)

Formula

G.f. A(x) satisfies: A(x) = 1 + 2*x + 4*x^2 + 8*x^3 + 16*x^4 + 32*x^5 + x^6*A(x/(1 + x))/(1 + x). - Ilya Gutkovskiy, Feb 02 2022
a(n) = 2^n for n<6; otherwise a(n) = Sum_{j=0..n-6} a(n-6-j)*binomial(n-6,j)*(-1)^j. - Michel Marcus, Mar 08 2023

A350456 G.f. A(x) satisfies: A(x) = 1 + x + x^2 * A(x/(1 + 2*x)) / (1 + 2*x).

Original entry on oeis.org

1, 1, 1, -1, 1, -3, 17, -85, 385, -1767, 8929, -50633, 312705, -2036267, 13794417, -97295069, 717808897, -5549714767, 44868094145, -377741383697, 3298933836033, -29813463964115, 278462029910993, -2685972391332837, 26733375327601281, -274247228584531767
Offset: 0

Views

Author

Ilya Gutkovskiy, Feb 04 2022

Keywords

Comments

Shifts 2 places left under 2nd-order inverse binomial transform.

Crossrefs

Programs

  • Mathematica
    nmax = 25; A[] = 0; Do[A[x] = 1 + x + x^2 A[x/(1 + 2 x)]/(1 + 2 x) + O[x]^(nmax + 1) // Normal, nmax + 1]; CoefficientList[A[x], x]
    a[0] = a[1] = 1; a[n_] := a[n] = Sum[Binomial[n - 2, k] (-2)^k a[n - k - 2], {k, 0, n - 2}]; Table[a[n], {n, 0, 25}]

Formula

a(0) = a(1) = 1; a(n) = Sum_{k=0..n-2} binomial(n-2,k) * (-2)^k * a(n-k-2).

A351184 G.f. A(x) satisfies: A(x) = 1 + x + x^2 * A(x/(1 + 3*x)) / (1 + 3*x).

Original entry on oeis.org

1, 1, 1, -2, 4, -11, 55, -359, 2359, -15230, 100840, -716555, 5580145, -47230091, 425472229, -4013326982, 39379161136, -402010392971, 4279164575167, -47533936734179, 550239127112107, -6618018093867506, 82447377648018700, -1061324336149876667, 14095604842846277617
Offset: 0

Views

Author

Ilya Gutkovskiy, Feb 04 2022

Keywords

Comments

Shifts 2 places left under 3rd-order inverse binomial transform.

Crossrefs

Programs

  • Mathematica
    nmax = 24; A[] = 0; Do[A[x] = 1 + x + x^2 A[x/(1 + 3 x)]/(1 + 3 x) + O[x]^(nmax + 1) // Normal, nmax + 1]; CoefficientList[A[x], x]
    a[0] = a[1] = 1; a[n_] := a[n] = Sum[Binomial[n - 2, k] (-3)^k a[n - k - 2], {k, 0, n - 2}]; Table[a[n], {n, 0, 24}]

Formula

a(0) = a(1) = 1; a(n) = Sum_{k=0..n-2} binomial(n-2,k) * (-3)^k * a(n-k-2).

A351185 G.f. A(x) satisfies: A(x) = 1 + x + x^2 * A(x/(1 + 4*x)) / (1 + 4*x).

Original entry on oeis.org

1, 1, 1, -3, 9, -31, 153, -1075, 8689, -72031, 605201, -5282051, 49239225, -497094079, 5410919273, -62597718643, 759331611489, -9586004915007, 125701843190689, -1713676634245251, 24313707650733289, -358906747784541151, 5502327502961296825, -87382907614533531443
Offset: 0

Views

Author

Ilya Gutkovskiy, Feb 04 2022

Keywords

Comments

Shifts 2 places left under 4th-order inverse binomial transform.

Crossrefs

Programs

  • Mathematica
    nmax = 23; A[] = 0; Do[A[x] = 1 + x + x^2 A[x/(1 + 4 x)]/(1 + 4 x) + O[x]^(nmax + 1) // Normal, nmax + 1]; CoefficientList[A[x], x]
    a[0] = a[1] = 1; a[n_] := a[n] = Sum[Binomial[n - 2, k] (-4)^k a[n - k - 2], {k, 0, n - 2}]; Table[a[n], {n, 0, 23}]

Formula

a(0) = a(1) = 1; a(n) = Sum_{k=0..n-2} binomial(n-2,k) * (-4)^k * a(n-k-2).

A351186 G.f. A(x) satisfies: A(x) = 1 + x + x^2 * A(x/(1 + 5*x)) / (1 + 5*x).

Original entry on oeis.org

1, 1, 1, -4, 16, -69, 371, -2719, 24691, -243804, 2479276, -25931249, 284075601, -3320433179, 41744590941, -561939568544, 8008026088996, -119496752915869, 1854697111334891, -29870689367146379, 499291484226079551, -8668202648905259624, 156301404533216141576
Offset: 0

Views

Author

Ilya Gutkovskiy, Feb 04 2022

Keywords

Comments

Shifts 2 places left under 5th-order inverse binomial transform.

Crossrefs

Programs

  • Mathematica
    nmax = 22; A[] = 0; Do[A[x] = 1 + x + x^2 A[x/(1 + 5 x)]/(1 + 5 x) + O[x]^(nmax + 1) // Normal, nmax + 1]; CoefficientList[A[x], x]
    a[0] = a[1] = 1; a[n_] := a[n] = Sum[Binomial[n - 2, k] (-5)^k a[n - k - 2], {k, 0, n - 2}]; Table[a[n], {n, 0, 22}]

Formula

a(0) = a(1) = 1; a(n) = Sum_{k=0..n-2} binomial(n-2,k) * (-5)^k * a(n-k-2).

A351187 G.f. A(x) satisfies: A(x) = 1 + x + x^2 * A(x/(1 + 6*x)) / (1 + 6*x).

Original entry on oeis.org

1, 1, 1, -5, 25, -131, 793, -6137, 60049, -670919, 7930321, -96775853, 1225237609, -16333089227, 232150489129, -3531321746465, 57178717416097, -975918663642767, 17400776511175201, -322309002081819221, 6188520430773389881, -123166171374344928275, 2542231599282355411897
Offset: 0

Views

Author

Ilya Gutkovskiy, Feb 04 2022

Keywords

Comments

Shifts 2 places left under 6th-order inverse binomial transform.

Crossrefs

Programs

  • Mathematica
    nmax = 22; A[] = 0; Do[A[x] = 1 + x + x^2 A[x/(1 + 6 x)]/(1 + 6 x) + O[x]^(nmax + 1) // Normal, nmax + 1]; CoefficientList[A[x], x]
    a[0] = a[1] = 1; a[n_] := a[n] = Sum[Binomial[n - 2, k] (-6)^k a[n - k - 2], {k, 0, n - 2}]; Table[a[n], {n, 0, 22}]

Formula

a(0) = a(1) = 1; a(n) = Sum_{k=0..n-2} binomial(n-2,k) * (-6)^k * a(n-k-2).

A379781 a(1)=1, a(2)=2; thereafter, a(n) is the final value at the bottom of the difference triangle of the sequence thus far.

Original entry on oeis.org

1, 2, 1, -2, 0, 7, -14, -12, 155, -408, -364, 7693, -30940, 10712, 637701, -4224222, 9980180, 61922567, -810337234, 4100137008, -958593005, -174952472228, 1662063951016, -6944673371867, -22887336602200, 655644589917172, -5694691183524699, 19946666531550638, 176993602416669640
Offset: 1

Views

Author

Neal Gersh Tolunsky, Jan 02 2025

Keywords

Comments

The difference triangle refers to the triangular array of iterated differences.
The first term in each row of the difference triangle is the inverse binomial transform of the sequence, so the definition means the inverse binomial transform deletes term a(2) = 2.

Examples

			To find a(6), we look at the first difference triangle of the first 5 terms:
  1,   2,   1,  -2,   0
  1,  -1,  -3,   2
 -2,  -2,   5
  0,   7
  7
7 is the final value, so a(6)=7.
		

Crossrefs

Programs

  • Mathematica
    a[1] = 1; a[2] = 2; a[n_] := a[n] = Sum[(-1)^(n-k+1) * Binomial[n-2, k-1] * a[k], {k, 1, n-1}]; Table[a[n], {n, 1, 30}] (* Amiram Eldar, Jan 04 2025 *)
Showing 1-10 of 10 results.