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.

A083216 Fibonacci-like sequence of composite numbers with a(0) = 20615674205555510, a(1) = 3794765361567513.

Original entry on oeis.org

20615674205555510, 3794765361567513, 24410439567123023, 28205204928690536, 52615644495813559, 80820849424504095, 133436493920317654, 214257343344821749, 347693837265139403, 561951180609961152, 909645017875100555, 1471596198485061707, 2381241216360162262
Offset: 0

Views

Author

Harry J. Smith, Apr 23 2003

Keywords

Comments

a(0) = 20615674205555510, a(1) = 3794765361567513. This is a second-order linear recurrence sequence with a(0) and a(1) coprime that does not contain any primes. It was found by Herbert S. Wilf in 1990.

Crossrefs

Programs

  • Maple
    a:= n-> (<<0|1>, <1|1>>^n. <<20615674205555510, 3794765361567513>>)[1, 1]:
    seq(a(n), n=0..20);  # Alois P. Heinz, Apr 04 2013
  • Mathematica
    LinearRecurrence[{1,1},{20615674205555510,3794765361567513},25] (* Paolo Xausa, Nov 07 2023 *)
  • PARI
    Vec((20615674205555510-16820908843987997*x)/(1-x-x^2)+O(x^9)) \\ Charles R Greathouse IV, Sep 23 2012

Formula

a(n) = a(n-1) + a(n-2) for n>1.
G.f.: (20615674205555510-16820908843987997*x)/(1-x-x^2).

A083104 Second-order linear recurrence sequence with a(n) = a(n-1) + a(n-2), with initial terms 331635635998274737472200656430763, 1510028911088401971189590305498785.

Original entry on oeis.org

331635635998274737472200656430763, 1510028911088401971189590305498785, 1841664547086676708661790961929548, 3351693458175078679851381267428333, 5193358005261755388513172229357881, 8545051463436834068364553496786214
Offset: 0

Views

Author

Harry J. Smith, Apr 23 2003

Keywords

Comments

This is a second-order linear recurrence sequence with a(0) and a(1) coprime that does not contain any primes. It was found by Ronald Graham in 1964.

Crossrefs

Cf. A000032 (Lucas numbers), A000045 (Fibonacci numbers), A083103, A083105, A083216, A082411, A221286.

Programs

  • Mathematica
    LinearRecurrence[{1,1},{331635635998274737472200656430763,1510028911088401971189590305498785},7] (* Harvey P. Dale, Oct 29 2016 *)
  • PARI
    a(n)=331635635998274737472200656430763*fibonacci(n-1)+ 1510028911088401971189590305498785*fibonacci(n) \\ Charles R Greathouse IV, Dec 18 2014

Formula

G.f.: (331635635998274737472200656430763+1178393275090127233717389649068022*x)/(1-x-x^2). - Colin Barker, Jun 19 2012

Extensions

Name clarified by Robert C. Lyons, Feb 07 2025

A083105 Second-order linear recurrence sequence with a(n) = a(n-1) + a(n-2), with initial terms 62638280004239857, 49463435743205655.

Original entry on oeis.org

62638280004239857, 49463435743205655, 112101715747445512, 161565151490651167, 273666867238096679, 435232018728747846, 708898885966844525, 1144130904695592371, 1853029790662436896, 2997160695358029267, 4850190486020466163, 7847351181378495430
Offset: 0

Views

Author

Harry J. Smith, Apr 23 2003

Keywords

Comments

a(0) = 62638280004239857, a(1) = 49463435743205655. This is a second-order linear recurrence sequence with a(0) and a(1) coprime that does not contain any primes. It was found by D. E. Knuth in 1990.

Crossrefs

Cf. A000032 (Lucas numbers), A000045 (Fibonacci numbers), A083103, A083104, A083216, A082411, A221286.

Programs

  • Maple
    a:= n-> (<<0|1>, <1|1>>^n. <<62638280004239857, 49463435743205655>>)[1, 1]:
    seq(a(n), n=0..20);  # Alois P. Heinz, Sep 20 2021
  • Mathematica
    LinearRecurrence[{1,1},{62638280004239857,49463435743205655},20] (* Paolo Xausa, Nov 07 2023 *)

Formula

G.f.: (62638280004239857-13174844261034202*x)/(1-x-x^2). [Colin Barker, Jun 19 2012]

Extensions

Name clarified by Robert C. Lyons, Feb 07 2025

A082411 Second-order linear recurrence sequence with a(n) = a(n-1) + a(n-2), with initial terms 407389224418, 76343678551.

Original entry on oeis.org

407389224418, 76343678551, 483732902969, 560076581520, 1043809484489, 1603886066009, 2647695550498, 4251581616507, 6899277167005, 11150858783512, 18050135950517, 29200994734029, 47251130684546, 76452125418575, 123703256103121, 200155381521696, 323858637624817
Offset: 0

Views

Author

Harry J. Smith, Apr 23 2003

Keywords

Comments

a(0) = 407389224418, a(1) = 76343678551. This is a second-order linear recurrence sequence with a(0) and a(1) coprime that does not contain any primes. It was found by John Nicol in 1999.

Crossrefs

Cf. A000032 (Lucas numbers), A000045 (Fibonacci numbers), A083103, A083104, A083105, A083216, A221286.

Programs

  • Maple
    a:= n-> (<<0|1>, <1|1>>^n. <<407389224418, 76343678551>>)[1, 1]:
    seq(a(n), n=0..20);  # Alois P. Heinz, Apr 04 2013
  • Mathematica
    LinearRecurrence[{1,1},{407389224418,76343678551},25] (* Paolo Xausa, Nov 07 2023 *)

Formula

G.f.: (407389224418-331045545867*x)/(1-x-x^2). [Colin Barker, Jun 19 2012]

Extensions

Name clarified by Robert C. Lyons, Feb 07 2025
Showing 1-4 of 4 results.