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.

A110544 Decimal expansion of -Integral {x=1..2} log gamma(x) dx.

Original entry on oeis.org

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

Views

Author

Robert G. Wilson v, Jul 25 2005

Keywords

Examples

			0.081061466795327258219670263594382360138602526362216587182848459...
		

References

  • Steven R. Finch, Mathematical Constants, Encyclopedia of Mathematics and its Applications, vol. 94, Cambridge University Press, 2003, Section 2.21, p. 168.

Crossrefs

Programs

  • Mathematica
    RealDigits[ N[ -Integrate[ Log[ Gamma[ x]], {x, 1, 2}], 128], 10, 128]
    RealDigits[ 1/2*Log[2*Pi]-1, 10, 105] // First // Prepend[#, 0]& (* Jean-François Alcover, Jun 10 2013 *)
  • PARI
    -intnum(x=1, 2, log(gamma(x))) \\ Michel Marcus, Jul 05 2020

Formula

Equals zeta'(0)+1 = -1/2*log(2*Pi)+1. - Jean-François Alcover, Jun 10 2013
From Amiram Eldar, Jul 05 2020: (Start)
Equals Sum_{k>=2} (1/(k + 1) - 1/(2*k))*(zeta(k)-1).
Equals Integral_{x=0..1} (1/2 - 1/(1 - x) - 1/log(x)) dx/log(x). (End)
Equals -Integral_{x=1..oo} ({x}-1/2)/x dx, where {.} is the fractional part [Nahin]. - R. J. Mathar, May 16 2024
Equals 1 - A075700 = log(A229495). - Hugo Pfoertner, Sep 05 2024
Equals log(2) - (gamma+1)/2 - Sum_{k>=2} (-1)^k*(zeta(k)-1)/(k+1), where gamma is Euler's constant (A001620) (Jakimczuk, 2025). - Amiram Eldar, May 30 2025

A384455 Decimal expansion of Sum_{k>=2} (-1)^k*P(k)/(k+1) - M/2 (negated), where P(s) is the prime zeta function and M is Mertens's constant.

Original entry on oeis.org

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

Views

Author

Amiram Eldar, May 30 2025

Keywords

Comments

The constant C in Theorem 2.2 in Jakimczuk (2025): Product_{p prime <= x} (1 + 1/p)^p = exp(PrimePi(x) + C)/sqrt(log(x)) + O(exp(PrimePi(x))/(sqrt(log(x))*exp(a*sqrt(log(x))))), where a is a positive constant, and Product_{k=1..n} (1 + 1/prime(k))^prime(k) = (exp(n + C)/sqrt(log(n))) * (1 - log(log(n))/(2*log(n)) + o(log(log(n))/log(n))).

Examples

			-0.01253463419149670110397060725717716746329257223331...
		

Crossrefs

Cf. A000720 (PrimePi), A001620, A077761 (Mertens's constant), A110544 (analogous with product over positive integers), A229495.

Programs

  • PARI
    suminf(k = 2, (1/(2*k) + (-1)^k/(k+1)) * sumeulerrat(1/p^k)) - Euler/2

Formula

Equals -gamma/2 + Sum_{k>=2} (1/(2*k) + (-1)^k/(k+1)) * P(k), where P(s) is the prime zeta function and gamma is Euler's constant (A001620).
Showing 1-2 of 2 results.