cp's OEIS Frontend

A082855 a(0)=0, a(1)=1, a(n) = A014137(A081288(n-1)-1).

%I A082855 #6 Apr 28 2020 06:36:28
%S A082855 0,1,2,4,4,4,9,9,9,9,9,9,9,9,9,23,23,23,23,23,23,23,23,23,23,23,23,23,
%T A082855 23,23,23,23,23,23,23,23,23,23,23,23,23,23,23,65,65,65,65,65,65,65,65,
%U A082855 65,65,65,65,65,65,65,65,65,65,65,65,65,65,65,65,65,65,65,65,65,65,65
%N A082855 a(0)=0, a(1)=1, a(n) = A014137(A081288(n-1)-1).
%C A082855 After n>0, A014137(n) occurs A000245(n) times.
%o A082855 (Scheme) (define (A082855 n) (if (< n 2) n (A014137 (-1+ (A081288 (-1+ n))))))
%o A082855 (PARI) A014137(n) = sum(k=0, n, binomial(2*k, k)/(k+1););
%o A082855 A081288(n) = my(i=0); while(binomial(2*i, i)/(i+1) <= n, i++); i;
%o A082855 a(n) = if (n<=1, n, A014137(A081288(n-1)-1)); \\ _Michel Marcus_, Apr 28 2020
%Y A082855 Cf. A081289, A082852. A081291(n) = n+A082855(n+1) for n>0.
%K A082855 nonn
%O A082855 0,3
%A A082855 _Antti Karttunen_, Apr 17 2003