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!)
 A086596 An invariant of the set {Log(2), Log(3), Log(5),..., Log(Prime(2n)), Log(Prime(2n+1))}. 2
 1, -1, 3, -8, 22, -53, 158, -481, 1471, -4621, 14612 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS This sequence comes from a corrected and extended example in the paper by Besser and Moree. LINKS A. Besser, P. Moree, On an invariant related to a linear inequality, Arch. Math. 79: pp. 463-471 D. Gijswijt and P. Moree, A set-theoretic invariant, arXiv:math/0309318 (2003) FORMULA a(t)=(-1)^t/2 sum_{d|p_1...p_t, d <= sqrt{p_1...p_t} mu(d). MATHEMATICA Invariant[a_List] := Module[{i=1, j=2, xMin, xMax, aa, n, invar=0, signs, x}, xMin=Abs[a[[i]]-a[[j]]]; xMax=a[[i]]+a[[j]]; aa=Complement[a, {a[[i]], a[[j]]}]; n=Length[aa]; Do[signs=(2*IntegerDigits[k, 2, n]-1); x=aa.signs; If[x>xMin&&x

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 July 24 12:47 EDT 2021. Contains 346273 sequences. (Running on oeis4.)