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.

A084448 Decimal expansion of (negative of) Kinkelin constant.

Original entry on oeis.org

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

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Author

N. J. A. Sloane, Jun 27 2003

Keywords

Comments

Named after the Swiss mathematician Hermann Kinkelin (1832-1913). - Amiram Eldar, Jun 16 2021

Examples

			-0.1654211437004509292139196602427806427640363803352017836665223...
		

Crossrefs

Programs

Formula

Zeta(1, -1). Almkvist gives many formulas.
Equals (1 - gamma - log(2*Pi))/12 + Zeta'(2)/(2*Pi^2), where gamma is the Euler-Mascheroni constant A001620. - Vaclav Kotesovec, Jul 25 2015
From Amiram Eldar, Jun 16 2021: (Start)
Equals 1/24 - gamma/3 - Sum_{k>=1} (zeta(2*k+1)-1)/((2*k+1)*(2*k+3)) = 1/12 - log(A), where A is the Glaisher-Kinkelin constant (A074962) (Kinkelin, 1860).
Equals 2 * Integral_{x>=0} x*log(x)/(exp(2*Pi*x)-1) dx = 2*A261819. (Wright, 1931). (End)

A262531 Minimal nested palindromic primes with seed 000.

Original entry on oeis.org

1300031, 10130003101, 171013000310171, 91710130003101719, 3917101300031017193, 16391710130003101719361, 10116391710130003101719361101, 191011639171013000310171936110191, 91910116391710130003101719361101919, 119191011639171013000310171936110191911
Offset: 2

Views

Author

Clark Kimberling, Sep 24 2015

Keywords

Comments

Let s be a palindrome and put a(1) = s. Let a(2) be the least palindromic prime having s in the middle; for n > 2, let a(n) be the least palindromic prime having a(n-1) in the middle. Then (a(n)) is the sequence of minimal nested palindromic primes with seed s. (For A261819, the seed is not an integer, so that the offset is 2.)

Examples

			As a triangle:
          000
        1300031
      10130003101
    171013000310171
   91710130003101719
  3917101300031017193
16391710130003101719361
		

Crossrefs

Cf. A261881.

Programs

  • Mathematica
    s0 = "000"; s = {ToExpression[s0]};Do[NestWhile[# + 1 &, 1, ! PrimeQ[tmp = FromDigits[Join[#, IntegerDigits[Last[s], 10, Max[StringLength[s0],Length[IntegerDigits[Last[s]]]]], Reverse[#]]&[IntegerDigits[#]]]] &]; AppendTo[s, tmp], {10}]; s0 <> ", " <> StringTake[ToString[Rest[s]], {2, -2}]
    (* Peter J. C. Moses, Sep 23 2015 *)
Showing 1-2 of 2 results.