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 1-5 of 5 results.

A060926 Row sums of triangle A060923 (even part of bisection of Lucas triangle).

Original entry on oeis.org

1, 5, 29, 149, 765, 3941, 20301, 104565, 538589, 2774149, 14289005, 73599381, 379093501, 1952623525, 10057515149, 51803949749, 266830242845, 1374381274821, 7079122173101, 36462931836885
Offset: 0

Views

Author

Wolfdieter Lang, Apr 20 2001

Keywords

Crossrefs

Cf. A060927 (Row sums of A060924).

Programs

  • Magma
    I:=[1,5,29]; [n le 3 select I[n] else 5*Self(n-1) + 4*Self(n-3): n in [1..30]]; // G. C. Greubel, Apr 09 2021
    
  • Mathematica
    LinearRecurrence[{5,0,4}, {1,5,29}, 31] (* G. C. Greubel, Apr 09 2021 *)
  • Sage
    def A060926_list(prec):
        P. = PowerSeriesRing(QQ, prec)
        return P( (1+4*x^2)/(1-5*x-4*x^3) ).list()
    A060926_list(30) # G. C. Greubel, Apr 09 2021

Formula

a(n) = Sum_{j=0..n} A060923(n, j).
a(n) = A060928(n) + 4*A060928(n-2), n >= 2, otherwise A060928(n).
G.f.: (1+4*x^2)/(1-5*x-4*x^3).

A060927 Row sums of triangle A060924 (odd part of bisection of Lucas triangle).

Original entry on oeis.org

3, 13, 65, 337, 1737, 8945, 46073, 237313, 1222345, 6296017, 32429337, 167036065, 860364393, 4431539313, 22825840825, 117570661697, 605579465737, 3119200691985, 16066286106713, 82753748396513
Offset: 0

Views

Author

Wolfdieter Lang, Apr 20 2001

Keywords

Crossrefs

Cf. A060926 (row sums of A060923 companion triangle).

Programs

  • Magma
    R:=PowerSeriesRing(Integers(), 30);
    Coefficients(R!( (3-2*x)/(1-5*x-4*x^3) )); // G. C. Greubel, Apr 07 2021
    
  • Mathematica
    CoefficientList[Series[(3-2*x)/(1-5*x-4*x^3), {x, 0, 30}], x] (* G. C. Greubel, Apr 07 2021 *)
  • Sage
    def A060927_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P( (3-2*x)/(1-5*x-4*x^3) ).list()
    A060927_list(30) # G. C. Greubel, Apr 07 2021

Formula

a(n) = Sum_{j=0..n} A060924(n, j).
G.f.: (3-2*x)/(1-5*x-4*x^3).
a(n) = 3*A060928(n) - 2*A060928(n-1), n >= 1; a(0)=3.

A032428 Coefficients of Jacobi elliptic function c(5,m).

Original entry on oeis.org

1, 99642, 116294673, 47152124264, 11966116940238, 2347836365864484, 393938089395885894, 59752013018382750024, 8470841585571575617239, 1146456994425541774291534, 150221961163114696686151695, 19239380962379456298762250416, 2424371762015227695363084225932
Offset: 5

Views

Author

Keywords

Crossrefs

Cf. A060928 (5th lower diagonal).

Formula

a(n) = T(2*n+1,0,5) where T(1,0,0) = 1; T(n,i,j) = 0 if i+j < 0 or i+j > n/2; T(2*n,i,j) = (2*j+1) * T(2*n-1,i,j) + (2*i+2) * T(2*n-1,i+1,j-1) + (2*n-2*i-2*j+1) * T(2*n-1,i,j-1), and T(2*n+1,i,j) = (2*i+1) * T(2*n-1,i,j) + (2*j+2) * T(2*n,i-1,j+1) + (2*n-2*i-2*j+2) * T(2*n-1,i-1,j). - Sean A. Irvine, Jun 20 2020

Extensions

Offset corrected and more terms from Sean A. Irvine, Jun 20 2020

A032427 Coefficients of Jacobi elliptic function c(4,m).

Original entry on oeis.org

1, 11069, 4494351, 834687179, 109645021894, 11966116940238, 1171517154238290, 107266611330420090, 9412382749388124015, 803475280086029066515, 67362921649153881472361, 5581153512072331417781229
Offset: 0

Views

Author

Keywords

Crossrefs

Cf. A060928 (4th lower diagonal).

Programs

  • Maple
    a:=proc(n) options remember: local m: if n>2 then if n mod 2 = 0 then m:=n/2-1: RETURN(-4*(1+k^2)*a(n-2)+6*k^2*add(binomial(n-2,2*v)*a(2*v)*a(n-2-2*v),v=1..m-1)) else m:=(n-1)/2-1: RETURN(-(1+k^2)*a(n-2)+2*k^2*add(binomial(n-2,2*v+1)*a(2*v+1)*a(n-3-2*v),v=0..m-1)) fi else RETURN([1,2][n]) fi:end: seq(abs(coeff(a(2*i+1),k,8)),i=4..23); # Herman Jamke (hermanjamke(AT)fastmail.fm), Sep 25 2010
  • Mathematica
    a[n_] := a[n] = Module[{m}, If[n > 2, If[Mod[n, 2] == 0, m = n/2 - 1; Return[-4*(1 + k^2)*a[n - 2] + 6*k^2*Sum[Binomial[n - 2, 2*v]*a[2*v]*a[n - 2 - 2*v], {v, 1, m - 1}]], m = (n - 1)/2 - 1; Return[-(1 + k^2)*a[n - 2] + 2*k^2*Sum[Binomial[n - 2, 2*v + 1]*a[2*v + 1]*a[n - 3 - 2*v], {v, 0, m - 1}]]], Return[{1, 2}[[n]]]]];
    Table[Abs[Coefficient[a[2*i + 1], k, 8]], {i, 4, 15}] (* Jean-François Alcover, Jul 08 2022, after Herman Jamke's Maple code *)

Formula

a(n) = (3^(4*n+19) - (24*n+36)*7^(2*n+9) + (96*n^2+312*n+150)*5^(2*n+9) - (256*n^3+1344*n^2+1520*n+117)*3^(2*n+9) + 512*n^4+3584*n^3+6208*n^2+1336*n-846) / 196608. - Vaclav Kotesovec after Fransen, Jul 30 2013

Extensions

More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Sep 25 2010

A032429 Coefficients of Jacobi elliptic function c(6,m).

Original entry on oeis.org

1, 896803, 2949965020, 2504055894564, 1171517154238290, 393938089395885894, 107947764316226205276, 25835579116799316507780, 5632500127524872577252027, 1149330973559307337432235521, 223559382769795167319093086664, 41982964485265754951017173213880
Offset: 6

Views

Author

Keywords

Crossrefs

Cf. A060928 (6th lower diagonal).

Formula

a(n) = T(2*n+1,0,6) where T(1,0,0) = 1; T(n,i,j) = 0 if i+j < 0 or i+j > n/2; T(2*n,i,j) = (2*j+1) * T(2*n-1,i,j) + (2*i+2) * T(2*n-1,i+1,j-1) + (2*n-2*i-2*j+1) * T(2*n-1,i,j-1), and T(2*n+1,i,j) = (2*i+1) * T(2*n-1,i,j) + (2*j+2) * T(2*n,i-1,j+1) + (2*n-2*i-2*j+2) * T(2*n-1,i-1,j). - Sean A. Irvine, Jun 20 2020

Extensions

Offset corrected and more terms from Sean A. Irvine, Jun 20 2020
Showing 1-5 of 5 results.