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 1-4 of 4 results.

A162773 a(n) = ((2+sqrt(5))*(5+sqrt(5))^n + (2-sqrt(5))*(5-sqrt(5))^n)/2.

Original entry on oeis.org

2, 15, 110, 800, 5800, 42000, 304000, 2200000, 15920000, 115200000, 833600000, 6032000000, 43648000000, 315840000000, 2285440000000, 16537600000000, 119667200000000, 865920000000000, 6265856000000000, 45340160000000000
Offset: 0

Views

Author

Al Hakanson (hawkuu(AT)gmail.com), Jul 13 2009

Keywords

Comments

Binomial transform of A162772. Fifth binomial transform of A162963.

Crossrefs

Programs

  • Magma
    Z:=PolynomialRing(Integers()); N:=NumberField(x^2-5); S:=[ ((2+r)*(5+r)^n+(2-r)*(5-r)^n)/2: n in [0..19] ]; [ Integers()!S[j]: j in [1..#S] ]; // Klaus Brockhaus, Jul 19 2009
  • Mathematica
    LinearRecurrence[{10,-20},{2,15},30] (* Harvey P. Dale, Dec 24 2012 *)

Formula

a(n) = 10*a(n-1) - 20*a(n-2) for n > 1; a(0) = 2, a(1) = 15.
G.f.: (2-5*x)/(1-10*x+20*x^2).

Extensions

Edited and extended beyond a(5) by Klaus Brockhaus, Jul 19 2009
Formulae corrected and clarified by Harvey P. Dale, Dec 24 2012

A162771 a(n) = ((2+sqrt(5))*(3+sqrt(5))^n + (2-sqrt(5))*(3-sqrt(5))^n)/2.

Original entry on oeis.org

2, 11, 58, 304, 1592, 8336, 43648, 228544, 1196672, 6265856, 32808448, 171787264, 899489792, 4709789696, 24660779008, 129125515264, 676109975552, 3540157792256, 18536506851328, 97058409938944, 508204432228352
Offset: 0

Views

Author

Al Hakanson (hawkuu(AT)gmail.com), Jul 13 2009

Keywords

Comments

Binomial transform of A001077 without initial 1. Third binomial transform of A162963. Inverse binomial transform of A162772.

Crossrefs

Programs

  • Magma
    Z:=PolynomialRing(Integers()); N:=NumberField(x^2-5); S:=[ ((2+r)*(3+r)^n+(2-r)*(3-r)^n)/2: n in [0..20] ]; [ Integers()!S[j]: j in [1..#S] ]; // Klaus Brockhaus, Jul 19 2009
  • Mathematica
    LinearRecurrence[{6,-4},{2,11},30] (* Harvey P. Dale, Aug 15 2013 *)
    CoefficientList[Series[(2 - x) / (1 - 6 x + 4 x^2), {x, 0, 30}], x] (* Vincenzo Librandi, Aug 16 2013 *)

Formula

a(n) = 6*a(n-1) - 4*a(n-2) for n > 1; a(0) = 2, a(1) = 11. [corrected by Harvey P. Dale, Aug 15 2013]
G.f.: (2-x)/(1-6*x+4*x^2).
a(n) = 2^(n-1) * A002878(n+1). - Diego Rattaggi, Jun 16 2020
a(n) = Sum_{k>=1} binomial(k+n-1,n) * A000032(k) / 2^(k+1). - Diego Rattaggi, Aug 02 2020

Extensions

Edited and extended beyond a(5) by Klaus Brockhaus, Jul 19 2009

A162772 a(n) = ((2+sqrt(5))*(4+sqrt(5))^n + (2-sqrt(5))*(4-sqrt(5))^n)/2.

Original entry on oeis.org

2, 13, 82, 513, 3202, 19973, 124562, 776793, 4844162, 30208573, 188382802, 1174768113, 7325934082, 45685023413, 284894912402, 1776624041673, 11079148296962, 69090321917293, 430851944071762, 2686822011483873
Offset: 0

Views

Author

Al Hakanson (hawkuu(AT)gmail.com), Jul 13 2009

Keywords

Comments

Binomial transform of A162771. Fourth binomial transform of A162963. Inverse binomial transform of A162773.

Crossrefs

Programs

  • Magma
    Z:=PolynomialRing(Integers()); N:=NumberField(x^2-5); S:=[ ((2+r)*(4+r)^n+(2-r)*(4-r)^n)/2: n in [0..19] ]; [ Integers()!S[j]: j in [1..#S] ]; // Klaus Brockhaus, Jul 19 2009

Formula

a(n) = 8*a(n-1) - 11*a(n-1) for n > 1; a(0) = 2, a(1) = 13.
G.f.: (2-3*x)/(1-8*x+11*x^2).

Extensions

Edited and extended beyond a(5) by Klaus Brockhaus, Jul 19 2009

A162770 a(n) = ((2+sqrt(5))*(1+sqrt(5))^n + (2-sqrt(5))*(1-sqrt(5))^n)/2.

Original entry on oeis.org

2, 7, 22, 72, 232, 752, 2432, 7872, 25472, 82432, 266752, 863232, 2793472, 9039872, 29253632, 94666752, 306348032, 991363072, 3208118272, 10381688832, 33595850752, 108718456832, 351820316672, 1138514460672, 3684310188032
Offset: 0

Views

Author

Al Hakanson (hawkuu(AT)gmail.com), Jul 13 2009

Keywords

Comments

Binomial transform of A162963. Inverse binomial transform of A001077 without initial 1.

Crossrefs

Programs

  • Magma
    Z:=PolynomialRing(Integers()); N:=NumberField(x^2-5); S:=[ ((2+r)*(1+r)^n+(2-r)*(1-r)^n)/2: n in [0..24] ]; [ Integers()!S[j]: j in [1..#S] ]; // Klaus Brockhaus, Jul 19 2009
  • Mathematica
    LinearRecurrence[{2,4},{2,7},30] (* Harvey P. Dale, Jan 13 2015 *)

Formula

a(n) = 2*a(n-1) + 4*a(n-2) for n > 1; a(0) = 2, a(1) = 7.
G.f.: (2+3*x)/(1-2*x-4*x^2).
a(n) = 2^(n-1) * A000032(n+3). - Diego Rattaggi, Jun 24 2020

Extensions

Edited and extended beyond a(5) by Klaus Brockhaus, Jul 19 2009
Showing 1-4 of 4 results.