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.

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A273397 a(n) = Fibonacci(Catalan(n)).

Original entry on oeis.org

1, 1, 1, 5, 377, 267914296, 1725375039079340637797070384, 202401005213503038261932567177107618332887918916819829782797456368284639448671475316218754
Offset: 0

Views

Author

Waldemar Puszkarz, May 21 2016

Keywords

Comments

Next term, a(8), which has 299 digits, is too large to include. Counterpart to A273398.
The number of digits of a(n) grows faster than Fibonacci(n), in contrast to A273398, and faster than Catalan(n-2), but slower than Catalan(n-1) or Catalan(n).

Examples

			For n = 3, a(3) = Fibonacci(Catalan(3)) = Fibonacci(5) = 5.
		

Crossrefs

Cf. A000045 (Fibonacci), A000108(Catalan), A263986, A273398 (related sequences with Fibonacci and Catalan numbers), A281450.

Programs

  • Maple
    a:= n-> (<<0|1>, <1|1>>^(binomial(2*n, n)/(n+1)))[1, 2]:
    seq(a(n), n=0..8);  # Alois P. Heinz, Jan 20 2017
  • Mathematica
    Fibonacci[CatalanNumber[Range[0, 7]]]
  • PARI
    for(n=0,7, cn=binomial(2*n, n)/(n+1); print1(fibonacci(cn) ","))

Formula

a(n) = A000045(A000108(n)).

A273398 a(n) = Catalan(Fibonacci(n)).

Original entry on oeis.org

1, 1, 1, 2, 5, 42, 1430, 742900, 24466267020, 812944042149730764, 1759414616608818870992479875972, 254224158304000796523953440778841647086547372026600, 161115593562260183597018076262500259385225118963936327496691227156776984827584194180
Offset: 0

Views

Author

Waldemar Puszkarz, May 21 2016

Keywords

Comments

Next term, a(13), which has 137 digits, is too large to include. Counterpart to A273397.
The number of digits of a(n) grows fast exceeding 10^6 for n=32. It grows faster than Fibonacci(n-2) but slower than Fibonacci(n) or Fibonacci(n-1) and even slower than the same number for A273397 which grows faster than Fibonacci(n).

Examples

			For n=4, a(4)=Catalan(Fibonacci(4))=Catalan(3)=5.
		

Crossrefs

Cf. A000108(Catalan), A000045 (Fibonacci), A263986, A273397 (related sequences with Fibonacci and Catalan numbers).

Programs

  • Maple
    a:= n-> (f-> binomial(2*f, f)/(f+1))((<<0|1>, <1|1>>^n)[1, 2]):
    seq(a(n), n=0..12);  # Alois P. Heinz, Jan 20 2017
  • Mathematica
    CatalanNumber[Fibonacci[Range[0,12]]]
    Table[CatalanNumber[Fibonacci[n]], {n, 0,12}]
  • PARI
    for(n=0,12, fn=fibonacci(n); print1(binomial(2*fn, fn)/(fn+1) ","))

Formula

a(n) = A000108(A000045(n)).
Showing 1-2 of 2 results.