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 1-6 of 6 results.

A101293 a(n) = Lucas(n!).

Original entry on oeis.org

1, 1, 3, 18, 103682, 11981655542024930675232002
Offset: 0

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Author

Parthasarathy Nambi, Dec 21 2004

Keywords

Comments

The next term is too large to include.
The next term has 151 digits. - Harvey P. Dale, Jan 04 2018

Examples

			L(3!) = 18.
L(4!) = 103682.
		

Crossrefs

Programs

  • Maple
    a:= n-> (<<1|1>, <1|0>>^n!. <<2, -1>>)[1, 1]:
    seq(a(n), n=0..6);  # Alois P. Heinz, Jul 15 2025
  • Mathematica
    LucasL[Range[0,5]!] (* Harvey P. Dale, Jan 04 2018 *)

Formula

a(n) = A000032(A000142(n)).

A371322 Decimal expansion of Sum_{k>=1} 1/(2^k * Fibonacci(k!)).

Original entry on oeis.org

7, 6, 5, 6, 2, 6, 3, 4, 7, 9, 1, 2, 3, 5, 3, 3, 4, 7, 1, 3, 5, 9, 5, 5, 8, 3, 7, 4, 4, 0, 0, 1, 4, 6, 3, 2, 9, 6, 0, 0, 0, 7, 7, 1, 6, 6, 2, 9, 1, 2, 5, 7, 2, 9, 9, 6, 3, 2, 5, 4, 5, 3, 5, 7, 4, 6, 5, 1, 8, 1, 5, 4, 7, 5, 9, 6, 4, 5, 2, 3, 2, 6, 3, 2, 5, 4, 6, 8, 0, 7, 6, 1, 6, 5, 7, 9, 7, 2, 1, 7, 3, 6, 4, 2, 3
Offset: 0

Views

Author

Amiram Eldar, Mar 19 2024

Keywords

Comments

The transcendence of this constant was proved by Nyblom (2001).

Examples

			0.76562634791235334713595583744001463296000771662912...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[Sum[1/(2^k * Fibonacci[k!]), {k, 1, 10}], 10, 120][[1]]
  • PARI
    suminf(k = 1, 1/(2^k * fibonacci(k!)))

A371324 Decimal expansion of Sum_{k>=1} (-1)^(k+1)/(2^k * Fibonacci(k!)).

Original entry on oeis.org

2, 6, 5, 6, 2, 3, 6, 5, 2, 0, 8, 7, 6, 4, 6, 6, 5, 2, 8, 6, 4, 0, 4, 4, 1, 7, 4, 2, 2, 4, 0, 0, 3, 5, 9, 0, 8, 6, 2, 0, 0, 9, 0, 9, 6, 8, 9, 1, 3, 7, 5, 5, 5, 7, 4, 3, 0, 4, 7, 3, 3, 0, 7, 3, 1, 3, 1, 1, 5, 8, 0, 8, 3, 1, 3, 8, 2, 0, 5, 2, 5, 9, 3, 8, 2, 7, 4, 8, 9, 5, 9, 5, 3, 3, 6, 3, 7, 1, 0, 6, 9, 4, 3, 2, 5
Offset: 0

Views

Author

Amiram Eldar, Mar 19 2024

Keywords

Comments

The transcendence of this constant was proved by Nyblom (2004).

Examples

			0.26562365208764665286404417422400359086200909689137...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[-Sum[(-1/2)^k/Fibonacci[k!], {k, 1, 10}], 10, 120][[1]]
  • PARI
    suminf(k = 1, -(-1/2)^k/fibonacci(k!))

A261626 a(n) = Fibonacci(n!) - Fibonacci(n)!.

Original entry on oeis.org

0, 0, 0, 6, 46362, 5358359254990966640871720
Offset: 0

Views

Author

Altug Alkan, Sep 14 2015

Keywords

Examples

			For n = 1, a(n) = Fibonacci(n!) - Fibonacci(n)! = 1 - 1 = 0.
		

Crossrefs

Programs

  • PARI
    a(n) = fibonacci(n!) - fibonacci(n)!;
    vector(6, n, a(n-1))

Formula

a(n) = A063374(n) - A060001(n).
log log a(n) ~ n log n. - Charles R Greathouse IV, Sep 14 2015

A262776 a(n) = Fibonacci(n!) mod Fibonacci(n)!.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 20160, 1098377280, 10712200669548618240, 157910199555786679826546221836620444160, 12162675222629942931022379230724715707339402614012620710827200735689241600
Offset: 0

Views

Author

Altug Alkan, Oct 01 2015

Keywords

Comments

Inspired by A261626.
Is there a possibility of observing that a(n) = 0 for n > 5?

Examples

			a(0) = Fibonacci(0!) mod Fibonacci(0)! = 1 mod 1 = 0.
a(1) = Fibonacci(1!) mod Fibonacci(1)! = 1 mod 1 = 0.
a(2) = Fibonacci(2!) mod Fibonacci(2)! = 1 mod 1 = 0.
a(3) = Fibonacci(3!) mod Fibonacci(3)! = 8 mod 2 = 0.
a(4) = Fibonacci(4!) mod Fibonacci(4)! = 46368 mod 6 = 0.
		

Crossrefs

Programs

  • Magma
    [Fibonacci(Factorial(n)) mod Factorial(Fibonacci(n)): n in [0..10]]; // Vincenzo Librandi, Oct 01 2015
    
  • Mathematica
    Table[Mod[Fibonacci[n!], Fibonacci[n]!], {n, 0, 9}] (* Michael De Vlieger, Oct 01 2015 *)
  • PARI
    a(n) = fibonacci(n!) % fibonacci(n)!;
    vector(10, n, a(n-1))
    
  • Python
    from gmpy2 import fac, fib
    def A262776(n):
        if n < 2:
            return 0
        a, b, m = 0, 1, fac(fib(n))
        for i in range(fac(n)-1):
            b, a = (b+a) % m, b
        return int(b) # Chai Wah Wu, Oct 03 2015

Formula

a(n) = A063374(n) mod A060001(n), for n > 0.

Extensions

a(10) from Alois P. Heinz, Oct 01 2015

A371136 Decimal expansion of Sum_{k>=1} 1/Fibonacci(k!).

Original entry on oeis.org

2, 1, 2, 5, 0, 2, 1, 5, 6, 6, 5, 9, 7, 6, 5, 3, 5, 5, 4, 1, 7, 5, 2, 9, 3, 4, 9, 2, 3, 5, 2, 3, 7, 9, 9, 1, 7, 9, 3, 6, 2, 5, 7, 9, 7, 4, 2, 3, 0, 0, 2, 1, 9, 7, 8, 5, 6, 1, 8, 9, 5, 3, 1, 6, 4, 2, 1, 3, 6, 2, 1, 8, 0, 7, 4, 2, 0, 4, 9, 7, 9, 0, 6, 8, 7, 3, 2, 2, 5, 5, 0, 4, 2, 4, 8, 2, 3, 0, 0, 7, 2, 2, 8, 7, 8
Offset: 1

Views

Author

Amiram Eldar, Mar 12 2024

Keywords

Comments

Nyblom (2000) proved that this constant is transcendental.

Examples

			2.12502156659765355417529349235237991793625797423002...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[Sum[1/Fibonacci[k!], {k, 1, 10}], 10, 120][[1]]
  • PARI
    suminf(k = 1, 1/fibonacci(k!))

Formula

Equals Sum_{k>=1} 1/A063374(k).
Showing 1-6 of 6 results.