The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A269300 Leading term in the sifting limit for Buchstab's iteration sieve. 1
 2, 4, 4, 5, 1, 8, 5, 8, 6, 1, 3, 2, 4, 2, 5, 7, 4, 3, 8, 5, 1, 5, 6, 2, 8, 8, 0, 5, 7, 1, 8, 1, 0, 0, 7, 7, 8, 2, 4, 5, 7, 8, 2, 7, 6, 5, 3, 7, 5, 3, 7, 0, 8, 3, 1, 0, 9, 5, 6, 5, 8, 2, 7, 2, 0, 3, 8, 7, 0, 1, 6, 1, 6, 7, 8, 1, 4 (list; constant; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 REFERENCES George Greaves, Sieves in Number Theory (2001). See p. 4 and pp. 293-294. LINKS G. C. Greubel, Table of n, a(n) for n = 1..10000 N. C. Ankeny and H. Onishi, The general sieve, Acta Arithmetica 10 (1964/1965), pp. 31-62. See theorems 2.4 and 2.5. H. Iwaniec, J. van de Lune, and H. J. J. te Riele, The limits of Buchstab's iteration sieve, Indagationes Mathematicae 83:4 (1980), pp. 409-417. FORMULA 2*exp(li(2)-gamma-1)/log(2)^2, where gamma is Euler's constant A001620. EXAMPLE 2.44518586132425743851562880571810077824578276537537083109565827203870... MATHEMATICA RealDigits[2*Exp[LogIntegral[2] - EulerGamma - 1]/Log[2]^2, 10, 100][[1]] (* G. C. Greubel, Sep 07 2018 *) PROG (PARI) 2*exp(intnum(s=0, log(2), (exp(s)-1)/s)-log(log(2))-1) (PARI) 2*exp(real(-eint1(-log(2)))-Euler-1)/log(2)^2 CROSSREFS Cf. A001620. Sequence in context: A009292 A009622 A232845 * A182215 A036443 A036437 Adjacent sequences:  A269297 A269298 A269299 * A269301 A269302 A269303 KEYWORD nonn,cons AUTHOR Charles R Greathouse IV, Feb 22 2016 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified February 28 23:19 EST 2020. Contains 332353 sequences. (Running on oeis4.)