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.

A271547 Decimal expansion of Product_{p prime} (1+1/(2p))*sqrt(1-1/p), a constant related to the asymptotic average number of squares modulo n.

Original entry on oeis.org

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

Views

Author

Jean-François Alcover, Apr 10 2016

Keywords

Examples

			0.81210571116312251170625096458188717656057710048366992436092182...
		

Crossrefs

Programs

  • Mathematica
    digits = 100; Exp[NSum[-( (-1)^n + 2^(n - 1))*PrimeZetaP[n]/(n* 2^n), {n, 2, Infinity}, NSumTerms -> 3 digits, WorkingPrecision -> digits + 10]] // RealDigits[#, 10, digits]& // First

Formula

Equals exp(Sum_{n>=2} -((-1)^n + 2^(n-1))*P(n)/(n*2^n)), where P(n) is the prime zeta P function.