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 1-2 of 2 results.

A048586 Pisot sequence L(6,8).

Original entry on oeis.org

6, 8, 11, 16, 24, 36, 54, 81, 122, 184, 278, 421, 638, 967, 1466, 2223, 3371, 5112, 7753, 11759, 17835, 27051, 41030, 62233, 94394, 143176, 217169, 329402, 499638, 757853, 1149515, 1743590, 2644686, 4011473, 6084623, 9229188, 13998881, 21233577, 32207203
Offset: 0

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Author

Keywords

Crossrefs

Subsequence of A048583. See A008776 for definitions of Pisot sequences.

Programs

  • Maple
    L := proc(a0,a1,n)
        option remember;
        if n = 0 then
            a0 ;
        elif n = 1 then
            a1;
        else
            ceil( procname(a0,a1,n-1)^2/procname(a0,a1,n-2)) ;
        end if;
    end proc:
    A048586 := proc(n)
        L(6,8,n) ;
    end proc: # R. J. Mathar, Feb 12 2016
  • Mathematica
    L[a0_, a1_, n_] := L[a0, a1, n] = Switch[n, 0, a0, 1, a1, _, Ceiling[L[a0, a1, n-1]^2/L[a0, a1, n-2]]];
    a[n_] := L[6, 8, n];
    Table[a[n], {n, 0, 50}] (* Jean-François Alcover, Oct 25 2023, after R. J. Mathar *)
  • PARI
    pisotL(nmax, a1, a2) = {
      a=vector(nmax); a[1]=a1; a[2]=a2;
      for(n=3, nmax, a[n] = ceil(a[n-1]^2/a[n-2]));
      a
    }
    pisotL(50, 6, 8) \\ Colin Barker, Aug 07 2016

A277088 Pisot sequences L(5,12), S(5,12).

Original entry on oeis.org

5, 12, 29, 71, 174, 427, 1048, 2573, 6318, 15514, 38095, 93544, 229702, 564045, 1385042, 3401044, 8351444, 20507414, 50357044, 123654396, 303639937, 745603993, 1830870208, 4495799044, 11039673351, 27108504296, 66566372193, 163457262657, 401377990645
Offset: 0

Views

Author

Ilya Gutkovskiy, Sep 29 2016

Keywords

Crossrefs

Cf. A008776 for definitions of Pisot sequences.
Cf. A000129 (with offset 3 appears to be Pisot sequences E(5,12), P(5,12)).

Programs

  • Mathematica
    RecurrenceTable[{a[0] == 5, a[1] == 12, a[n] == Ceiling[a[n - 1]^2/a[n - 2]]}, a, {n, 28}]
    RecurrenceTable[{a[0] == 5, a[1] == 12, a[n] == Floor[a[n - 1]^2/a[n - 2] + 1]}, a, {n, 28}]

Formula

a(n) = ceiling(a(n-1)^2/a(n-2)), a(0) = 5, a(1) = 12.
a(n) = floor(a(n-1)^2/a(n-2)+1), a(0) = 5, a(1) = 12.
Conjectures: (Start)
G.f.: (5 - 3*x + 3*x^2 - 2*x^3 + x^5 - 3*x^6 - x^7 - 2*x^8)/((1 - x)*(1 - 2*x - 2*x^3 - x^4 - x^5 - 2*x^6 - x^7 - x^8)).
a(n) = 3*a(n-1) - 2*a(n-2) + 2*a(n-3) - a(n-4) + a(n-6) - a(n-7) - a(n-9). (End)
Showing 1-2 of 2 results.