cp's OEIS Frontend

A198759 The number of pairs of braces to note the properly nested set with n elements.

%I A198759 #20 Dec 23 2024 14:53:42
%S A198759 1,2,4,7,11,15,20,25,30,36,42,48,54,60,66,73,80,87,94,101,108,115,122,
%T A198759 129,136,143,150,158,166,174,182,190,198,206,214,222,230,238,246,254,
%U A198759 262,270,278,286,294,302,310,318,326,334,342,350,359,368,377,386,395
%N A198759 The number of pairs of braces to note the properly nested set with n elements.
%H A198759 Alois P. Heinz, <a href="/A198759/b198759.txt">Table of n, a(n) for n = 0..20000</a>
%H A198759 F. T. Adams-Watters, <a href="https://web.archive.org/web/*/http://list.seqfan.eu/oldermail/seqfan/2011-October/015746.html">Re: Set of sets using minimal number of braces</a>, SeqFan Oct 29 2011
%H A198759 J. Zucker, <a href="https://web.archive.org/web/*/http://list.seqfan.eu/oldermail/seqfan/2011-October/015683.html">Set of sets using minimal number of braces</a>, SeqFan Oct 25 2011
%p A198759 # implementing the Adams-Watters partial sum formula up to nmax elements
%p A198759 read("transforms") ;
%p A198759 nmax := 40 ;
%p A198759 a004111rep := [1,1] ;
%p A198759 n := 2 ;
%p A198759 while nops(a004111rep) < nmax do
%p A198759         a004111rep := [op(a004111rep),seq(n,i=1..A004111(n))] ;
%p A198759         n := n+1 ;
%p A198759 end do:
%p A198759 PSUM(a004111rep) ;
%Y A198759 Cf. A004111.
%K A198759 nonn
%O A198759 0,2
%A A198759 _R. J. Mathar_, Oct 29 2011