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!)
 A028304 a(n) = ceiling((1/(ceiling(n/2)+1))*binomial(n,floor(n/2))) (interpolates between Catalan numbers). 1
 1, 1, 1, 1, 2, 3, 5, 7, 14, 21, 42, 66, 132, 215, 429, 715, 1430, 2431, 4862, 8398, 16796, 29393, 58786, 104006, 208012, 371450, 742900, 1337220, 2674440, 4847423, 9694845, 17678835, 35357670, 64822395 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,5 REFERENCES D. Miklos et al., eds., Combinatorics, Paul ErdÅ‘s is Eighty, Bolyai Math. Soc., 1993, Vol. 1, p. 101. LINKS FORMULA a(2*n) = A000108(n), a(2*n+1) = A130380(n+1). - R. J. Mathar, Dec 15 2015 MAPLE A028304 := proc(n)     A001405(n)/(ceil(n/2)+1) ;     ceil(%) ; end proc: # R. J. Mathar, Dec 15 2015 MATHEMATICA Table[Ceiling[(1/(Ceiling[n/2] + 1)) Binomial[n, Floor[n/2]]], {n, 0, 49}] (* Alonso del Arte, Oct 30 2019 *) CROSSREFS Cf. A000108, A000245, A130380. Sequence in context: A046808 A097799 A005629 * A324840 A316475 A303875 Adjacent sequences:  A028301 A028302 A028303 * A028305 A028306 A028307 KEYWORD nonn AUTHOR 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 09:40 EST 2020. Contains 332323 sequences. (Running on oeis4.)