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 11-16 of 16 results.

A123561 Continued fraction expansion of Mills' constant.

Original entry on oeis.org

1, 3, 3, 1, 3, 1, 2, 1, 2, 1, 4, 2, 35, 21, 1, 4, 4, 1, 1, 3, 2, 17, 7, 4, 1, 3, 16, 5, 3, 2, 3, 1, 4, 8, 1, 1, 19578, 1, 1, 1, 1, 1, 8, 1, 2, 1, 1, 3, 2, 1, 1, 1, 2, 1, 1, 9, 1, 1, 1, 2, 14, 4, 19, 1, 3, 3, 5, 9, 1, 3, 1, 6, 1, 2, 1, 11, 1, 1, 5, 23, 1, 4, 2, 3, 1, 35, 2, 1, 5, 3, 1, 9, 4, 8, 3, 1, 6, 2, 1
Offset: 0

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Author

Hauke Worpel (hw1(AT)email.com), Nov 11 2006

Keywords

Crossrefs

Cf. A051021 (decimal expansion), A051254.

Programs

  • Mathematica
    ContinuedFraction[Nest[NextPrime[#^3] &, 2, 7]^(1/3^8), 100] (* G. C. Greubel, Oct 25 2017 *)

Extensions

More terms from Robert G. Wilson v, Nov 18 2006
Offset changed by Andrew Howroyd, Aug 09 2024

A171883 Mills primes, starting with 3.

Original entry on oeis.org

3, 29, 24391, 14510715208481, 3055388613462301256452407743005777548691
Offset: 1

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Author

Robert Munafo, Feb 27 2010

Keywords

Comments

For the standard Mills primes sequence, A051254, one starts with 2, and each successive term a(n) is the smallest prime greater than a(n-1)^3. This sequence uses the same definition but starts with 3.
a(6) has 119 digits and is too large to include.

Crossrefs

Programs

  • Mathematica
    p = 36/25; Table[p = NextPrime[p^3], {6}] (* From Alonso del Arte based on T. D. Noe's program for A051254, Oct 05 2011 *)
    NestList[NextPrime[#^3]&,3,5] (* Harvey P. Dale, Feb 15 2014 *)
  • Maxima
    n:3 $ l:10^100 $ print(n) $ while (n
    				

Extensions

Offset corrected by Arkadiusz Wesolowski, Oct 05 2011

A300753 Decimal expansion of the constant B such that ceiling(B^(3^k)) = A118910(k) is prime for all k >= 0.

Original entry on oeis.org

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

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Author

Amiram Eldar, Jun 19 2018

Keywords

Comments

Tóth calculated the first 5500 decimal digits of this constant. The first 600 digits are presented in his paper.

Examples

			1.24055470525201424067469515337900345212353396725255...
		

Crossrefs

Formula

Lim_{n->oo} (A118910(n) - 1)^(3^(-n)).

A382261 a(n) = floor(x^(phi^n)), where phi = (1+sqrt(5))/2 and x is the constant A382260.

Original entry on oeis.org

2, 3, 7, 23, 163, 3803, 620549, 2359981439, 1464484123012601, 3456155348019933976288373, 5061484633840283809323162088349619180781, 17493277186167814180104995425523045477935447066389138909089293633
Offset: 1

Views

Author

Thomas Scheuerle, Mar 19 2025

Keywords

Comments

Conjecture: All terms are prime numbers. For details see A382260.

Crossrefs

Cf. A090253 ( similar growth ).

Formula

nextprime(a(n-2)*a(n-1)) <= a(n) < nextprime((a(n-2)+1)*a(n-1)).

A286682 a(n) = A059784(n+1) - A059784(n)^2.

Original entry on oeis.org

1, 4, 12, 4, 22, 12, 114, 4, 138, 142, 2956, 6388, 5248, 17532, 96930, 83782, 1464, 897448, 300832, 26908
Offset: 1

Views

Author

Jeppe Stig Nielsen, May 12 2017

Keywords

Comments

This sequence relates to A059784 just like A108739 relates to the Mills primes A051254.
That this leads to a Mills-like real constant C such that floor(C^2^n) is a prime number for any natural number n, requires a proof of Legendre's conjecture that there is always a prime between consecutive perfect squares.
a(18) and a(19) generate 96042- and 192083-decimal digit probable primes. - Serge Batalov, May 27 2024
a(20) generates a 384166-decimal digit probable prime. - Serge Batalov, May 27 2024

Examples

			A059784(8) by construction can be written ((((((2^2 + 1)^2 + 4)^2 + 12)^2 + 4)^2 + 22)^2 + 12)^2 + 114. Taking out the addends gives 1, 4, 12, 4, 22, 12, 114 which lists the first seven terms of this sequence.
		

Crossrefs

Programs

  • Mathematica
    Map[#2 - #1^2 & @@ # &, Partition[NestList[NextPrime[#^2] &, 2, 12], 2, 1]] (* Michael De Vlieger, May 12 2017 *)
  • PARI
    p=2;while(1,a=nextprime(p^2);print1(a-p^2,", ");p=a)

Extensions

a(14)-a(17) from Serge Batalov, May 26 2024
a(18)-a(20) from Serge Batalov, May 27 2024

A323828 Decimal expansion of a constant related to Bertrand's Postulate.

Original entry on oeis.org

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

Views

Author

N. J. A. Sloane, Feb 01 2019

Keywords

Examples

			3.5679760909846634612366007737192526425527943028977913311170116688989193092...
		

Crossrefs

Programs

  • Maple
    evalf(Sum((2^(k-1) + 1)/Product(2^(i-1) + 2, i=1..k-1), k=1..infinity), 120); # Vaclav Kotesovec, Jun 04 2019
  • Sage
    def g(n):
        return sum((2^(k-1) + 1)/prod(2^(i-1) + 2 for i in (1..k-1))
                   for k in (1..n))
    N(g(100), digits=102) # Freddy Barrera, Feb 17 2019

Formula

Sum_{k>=1} (2^(k-1) + 1)/(Product_{i=1..k-1} 2^(i-1) + 2). See Dylan Fridman et al. reference. - Freddy Barrera, Feb 17 2019

Extensions

More terms from Freddy Barrera, Feb 17 2019
Previous Showing 11-16 of 16 results.