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.

Previous Showing 11-14 of 14 results.

A273156 Product of all parts in Zeckendorf representation of n.

Original entry on oeis.org

0, 1, 2, 3, 3, 5, 5, 10, 8, 8, 16, 24, 24, 13, 13, 26, 39, 39, 65, 65, 130, 21, 21, 42, 63, 63, 105, 105, 210, 168, 168, 336, 504, 504, 34, 34, 68, 102, 102, 170, 170, 340, 272, 272, 544, 816, 816, 442, 442, 884, 1326, 1326, 2210, 2210, 4420, 55, 55, 110, 165
Offset: 0

Views

Author

Peter Kagey, May 16 2016

Keywords

Examples

			a(33) = 21*8*3*1 because 33 = 21+8+3+1.
		

Crossrefs

Programs

  • Haskell
    a273156 = product . a035516_row
  • Maple
    A273156 := proc(n)
        local nred,a,f ;
        if n = 0 then
            0;
        else
            nred := n ;
            a := 1 ;
            while nred > 1 do
                f := A087172(nred) ;
                a := a*f ;
                nred := nred-f ;
            end do:
            a ;
        end if;
    end proc: # R. J. Mathar, May 17 2016
  • Mathematica
    t = Fibonacci /@ Range@ 21; {0}~Join~Table[Times @@ If[MemberQ[t, n], {n}, Most@ MapAt[# + 1 &, Abs@ Differences@ FixedPointList[# - First@ Reverse@ TakeWhile[t, Function[k, # >= k]] &, n], -1]], {n, 58}] (* Michael De Vlieger, May 17 2016 *)
    a[0]=0; a[n_]:=Block[{m=n, p=1, f, k=0}, While[Fibonacci@ ++k <= n]; While[ m>1, f= Fibonacci@ --k; If[ f<=m, m-=f; p*=f]]; p]; Array[a, 80, 0] (* Giovanni Resta, May 17 2016 *)

A107227 Numbers having no odd terms in their Zeckendorf representation.

Original entry on oeis.org

2, 8, 10, 34, 36, 42, 44, 144, 146, 152, 154, 178, 180, 186, 188, 610, 612, 618, 620, 644, 646, 652, 654, 754, 756, 762, 764, 788, 790, 796, 798, 2584, 2586, 2592, 2594, 2618, 2620, 2626, 2628, 2728, 2730, 2736, 2738, 2762, 2764, 2770, 2772, 3194, 3196, 3202
Offset: 1

Views

Author

Reinhard Zumkeller, May 15 2005

Keywords

Comments

A107016(a(n))=0, A107015(a(n))>0; subsequence of A107225.

Crossrefs

Programs

  • Haskell
    a107227 n = a107227_list !! (n-1)
    a107227_list = filter ((all even) . a035516_row) [1..]
    -- Reinhard Zumkeller, Mar 10 2013

A107228 Numbers having no even terms in their Zeckendorf representation.

Original entry on oeis.org

1, 3, 4, 5, 6, 13, 14, 16, 17, 18, 19, 21, 22, 24, 25, 26, 27, 55, 56, 58, 59, 60, 61, 68, 69, 71, 72, 73, 74, 76, 77, 79, 80, 81, 82, 89, 90, 92, 93, 94, 95, 102, 103, 105, 106, 107, 108, 110, 111, 113, 114, 115, 116, 233, 234, 236, 237, 238, 239, 246, 247, 249, 250
Offset: 1

Views

Author

Reinhard Zumkeller, May 15 2005

Keywords

Comments

A107015(a(n))=0, A107016(a(n))>0; subsequence of A107224.

Crossrefs

Programs

  • Haskell
    a107228 n = a107228_list !! (n-1)
    a107228_list = filter ((all odd) . a035516_row) [1..]
    -- Reinhard Zumkeller, Mar 10 2013

A357120 Irregular triangle T(n, k), n > 0, k = 1..A278043(n); the n-th row contains, in ascending order, the terms in the greedy tribonacci representation of n.

Original entry on oeis.org

1, 2, 1, 2, 4, 1, 4, 2, 4, 7, 1, 7, 2, 7, 1, 2, 7, 4, 7, 1, 4, 7, 13, 1, 13, 2, 13, 1, 2, 13, 4, 13, 1, 4, 13, 2, 4, 13, 7, 13, 1, 7, 13, 2, 7, 13, 1, 2, 7, 13, 24, 1, 24, 2, 24, 1, 2, 24, 4, 24, 1, 4, 24, 2, 4, 24, 7, 24, 1, 7, 24, 2, 7, 24, 1, 2, 7, 24, 4, 7, 24
Offset: 1

Views

Author

Rémy Sigrist, Sep 12 2022

Keywords

Comments

See A357121 for the sequence corresponding to lazy tribonacci representations.

Examples

			Triangle T(n, k) begins:
     1: [1]
     2: [2]
     3: [1, 2]
     4: [4]
     5: [1, 4]
     6: [2, 4]
     7: [7]
     8: [1, 7]
     9: [2, 7]
    10: [1, 2, 7]
    11: [4, 7]
    12: [1, 4, 7]
    13: [13]
    14: [1, 13]
    15: [2, 13]
		

Crossrefs

Programs

  • PARI
    See Links section.

Formula

T(n, 1) = A275392(n).
Sum_{k = 1..A278043(n)} T(n, k) = n.
Previous Showing 11-14 of 14 results.