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.

A227929 Decimal expansion of 36/Pi^4.

Original entry on oeis.org

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

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Author

Arkadiusz Wesolowski, Oct 09 2013

Keywords

Comments

Ernesto Cesaro asserted that lim n -> infinity A002321(n)/n = 36/Pi^4 using a fallacious argument. In fact this limit equals zero.

Examples

			36/Pi^4 = 0.369575361168636066809500197....
		

References

  • Ernesto Cesaro, Sur diverses questions d'arithmetique. Mem. Soc. Roy. Sci. Liege 10 (1883), 1-350. Reprinted in Opere Scelte I, Vol. 1, pp. 10-362.
  • Wladyslaw Narkiewicz, The development of prime number theory: from Euclid to Hardy and Littlewood, Springer-Verlag, New York, 2000, p. 31.

Crossrefs

Programs

  • Magma
    pi:=Pi(RealField(107)); Reverse(Intseq(Floor(10^105*36/pi^4)));
    
  • Mathematica
    RealDigits[N[36/Pi^4, 105]][[1]]
  • PARI
    default(realprecision, 105); x=360/Pi^4; for(n=1, 105, d=floor(x); x=(x-d)*10; print1(d, ", "));

Formula

Equals Product_{primes p} (1 - 2/p^2 + 1/p^4). - Vaclav Kotesovec, Jun 20 2020
Equals 1/A098198. - R. J. Mathar, Jul 21 2025