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.

User: John Lien

John Lien's wiki page.

John Lien has authored 6 sequences.

A165221 The Padovan sequence analog of the Fibonacci "rabbit" constant binary expansion. Starting with 0 and using the transitions 0->1,1->10,10->01 the subsequences 0,1,10,01,110,1001,01110,1101001,100101110,011101101001... are formed where each subsequence has P sub n ones and length P sub (n-1) binary digits, where P sub n is the n-th Padovan number. This sequence is the concatenation of all the subsequences. Also note that the n-th subsequence is the concatenation of the n-th-3 and n-th-2 subsequences.

Original entry on oeis.org

0, 1, 0, 1, 1, 0, 0, 1, 1, 1, 0, 0, 1, 0, 1, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1
Offset: 1

Author

John Lien, Sep 08 2009

Keywords

A165263 A sequence similar to the Fibonacci rabbit sequence for the Padovan sequence.

Original entry on oeis.org

0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1, 1, 0
Offset: 1

Author

John Lien, Sep 12 2009

Keywords

Comments

Starting with 0,1 and using the maps 0->1 1->.10 and 10->01 Gives the subsequences 0,1,10,01,1.10,10.01,01.1.10,1.10.10.01 etc. The n-th subsequence has a 1 count equal to P(n) where P is the n-th Padovan sequence number (A000931) and a digit length P(n+2). This sequence represents the binary number formed by concatenating these sebsequences. Similar to how the Fibonacci rabbit constant is formed by the maps 0->1 1->10.

A126772 Padovan factorials: a(n) is the product of the first n terms of the Padovan sequence. Similar to the Fibonacci factorial.

Original entry on oeis.org

1, 1, 1, 2, 4, 12, 48, 240, 1680, 15120, 181440, 2903040, 60963840, 1706987520, 63158538240, 3094768373760, 201159944294400, 17299755209318400, 1972172093862297600, 297797986173206937600, 59559597234641387520000
Offset: 1

Author

John Lien, Feb 17 2007

Keywords

Crossrefs

Programs

  • Maple
    From R. J. Mathar, Sep 14 2010: (Start)
    A000931 := proc(n) option remember; if n = 0 then 1; elif n <=2 then 0; else procname(n-2)+procname(n-3) ; end if; end proc:
    A126772 := proc(n) mul( A000931(i),i=5..n+4) ; end proc: seq(A126772(n),n=1..40) ; (End)
  • Mathematica
    Rest[FoldList[Times,1,LinearRecurrence[{0,1,1},{1,1,1},30]]] (* Harvey P. Dale, Apr 29 2013 *)

Formula

a(n) ~ c * d^(n/2) * r^(n^2/2), where r = 1.324717957244746... (see A060006) is the root of the equation r^3 = r + 1, d = 0.393641282401116385386658448446561... is the root of the equation 1 + 7*d + 184*d^2 - 529*d^3 = 0, c = 1.25373683131537208838997864311903035079685338006712312402418098138010834953... (see A253924). - Vaclav Kotesovec, Jan 26 2015

Extensions

More terms from R. J. Mathar, Sep 14 2010

A100283 a(n) = floor(p*(n+1)) - floor(p*(n)) - 1 where p = Padovan plastic number = 1.324718... (cf. A060006).

Original entry on oeis.org

0, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1
Offset: 0

Author

John Lien, Dec 28 2004

Keywords

Comments

A rabbit-like sequence generated by the Padovan plastic number.
The well-known rabbit sequence is generated by taking the difference between the nearest integer less than phi*(n+1) minus the nearest integer less than phi*(n). If this value is 2, then the n-th rabbit sequence value is one. If this value is 1, the n-th rabbit sequence is 0. The sequence given is calculated in a similar manner, but using the plastic constant = 1.324717957244... instead of phi = 1.618033... = (1+sqrt(5))/2. It is 0001 followed by 11 copies of 001 followed by 0001 followed by 12 copies of 001 followed by 11 copies of 001 followed by similar patterns of 0001 followed by n copies of 001 where n is 11 or 12.

References

  • Midhat J. Gazale, Gnomon: From Pharaohs to Fractals, Princeton University Press, 1999

Crossrefs

Programs

  • PARI
    p=(sqrt(23/108)+.5)^(1/3) + (abs( sqrt(23/108) -.5))^(1/3); for(n = 0, n = 200, r = floor(p*(n+1)) - floor(p*n) -1; print (r ))

Extensions

Partially edited by N. J. A. Sloane, Jun 13 2007

A100538 Volume of the 3-dimensional box of sides of length equal to consecutive Padovan numbers (A000931). These boxes form a spiral in three dimensions similar to the spiral of Fibonacci boxes in two dimensions.

Original entry on oeis.org

1, 2, 4, 12, 24, 60, 140, 315, 756, 1728, 4032, 9408, 21756, 50764, 117845, 273910, 637260, 1480404, 3442800, 8003000, 18603000, 43251975, 100540440, 233735040, 543371136, 1263161472, 2936540824, 6826574552, 15869878969, 36893076570
Offset: 1

Author

John Lien, Nov 27 2004

Keywords

Comments

a(n)^(1/3) rounded to the nearest integer equals A000931(n+5). - Peter M. Chema, Apr 24 2017

Crossrefs

Cf. A000931.

Programs

  • Mathematica
    LinearRecurrence[{1, 2, 3, -2, 4, -4, -1, -1, 0, -1}, {1, 2, 4, 12, 24, 60, 140, 315, 756, 1728}, 50] (* Vincenzo Librandi, Apr 24 2017 *)

Formula

For large n a(n+1) -> a(n) * p^3 where p is the plastic number = 1.324718... a(n+1) = a(n)+ (a(n)/P(n))*P(n+1 ) where P are the Padovan numbers (A000931) starting 1, 1, 1, 2, 2, 3, 4, 5, 7, etc.
a(n) = +a(n-1) +2*a(n-2) +3*a(n-3) -2*a(n-4) +4*a(n-5) -4*a(n-6) -a(n-7) -a(n-8) -a(n-10) = A000931(n+4)*A000931(n+5)*A000931(n+6). G.f.: x*(1+x+x^3) / ( (x-1)*(x^3-2*x^2+3*x-1)*(x^6+3*x^5+5*x^4+5*x^3+5*x^2+3*x+1) ). - R. J. Mathar, Sep 14 2010

Extensions

More terms from R. J. Mathar, Sep 14 2010

A100891 Prime Padovan numbers.

Original entry on oeis.org

2, 3, 5, 7, 37, 151, 3329, 23833, 13091204281, 3093215881333057, 1363005552434666078217421284621279933627102780881053358473, 1558877695141608507751098941899265975115403618621811951868598809164180630185566719
Offset: 1

Author

John Lien, Jan 10 2005

Keywords

Comments

Next term corresponds to Padovan(1262) and has 154 decimal digits.

References

  • Midhat J. Gazale, "Gnomon: From Pharaohs to Fractals", Princeton University Press, 1999.

Crossrefs

Indices of prime Padovan numbers are A112882.

Programs

  • Mathematica
    Rest[Select[LinearRecurrence[{0,1,1},{1,1,2},1000],PrimeQ]] (* Harvey P. Dale, Mar 31 2012 *)

Extensions

More terms from Robert G. Wilson v, Jan 14 2005