OFFSET
1,2
COMMENTS
LINKS
Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
J.-P. Allouche and J. Shallit, The ring of k-regular sequences, Theoretical Computer Sci., 98 (1992), 163-197; preprint. See Example 33.
E. M. Reingold and R. E. Tarjan, On a greedy heuristic for complete matching, SIAM J. Computing 10 (1981), 676-681; Semantic Scholar.
FORMULA
A072403(n) / a(n) = 2 - Sum_{k=1..n} (1 / A000244(A029837(k)). - Reinhard Zumkeller, Jan 01 2013 [Corrected by Sean A. Irvine, Sep 28 2024]
PROG
(Haskell)
import Data.Ratio ((%), denominator)
a072404 n = a072404_list !! (n-1)
a072404_list = map denominator $
scanl1 (-) $ map ((1 %) . a000244) $ a029837_list
-- Reinhard Zumkeller, Jan 01 2013
CROSSREFS
KEYWORD
nonn,frac
AUTHOR
Reinhard Zumkeller, Jun 16 2002
STATUS
approved