cp's OEIS Frontend

A262888 a(n) = total number of nodes in the finite subtrees branching "left" (to the "smaller side") from node n in the infinite trunk (A259934) of the tree generated by edge-relation A049820(child) = parent.

%I A262888 #15 Oct 04 2015 13:10:57
%S A262888 6,0,41,0,0,5,0,16,0,2,0,0,1,24,4,0,0,0,0,0,0,0,105,2,0,0,0,3,18,7,0,
%T A262888 0,0,1,1,0,0,0,0,0,0,13,1,0,0,0,0,6,1,0,0,0,47,0,0,0,90,0,0,5,0,0,0,1,
%U A262888 0,0,12,0,0,3,61,0,0,0,0,0,0,1,117,7,0,2,10,0,0,1,23,0,1,1,0,0,1,0,0,0,0,2,2,2,568,0,1,1,4,0,5,9,0,0,0,0,0,8,0,1,1,0,2,10,1,1,0
%N A262888 a(n) = total number of nodes in the finite subtrees branching "left" (to the "smaller side") from node n in the infinite trunk (A259934) of the tree generated by edge-relation A049820(child) = parent.
%H A262888 Antti Karttunen, <a href="/A262888/b262888.txt">Table of n, a(n) for n = 0..8107</a>
%F A262888 a(n) = sum_{k = A082284(A259934(n)) .. A259934(n+1)} [A049820(k) = A259934(n)] * A262697(k).
%F A262888 (Here [ ] stands for Iverson bracket, giving as its result 1 only when A049820(k) = A259934(n), and 0 otherwise).
%F A262888 Other identities. For all n >= 0:
%F A262888 A262890(n) = a(n) + A262889(n).
%o A262888 (Scheme)
%o A262888 (define (A262888 n) (let ((t (A259934 n))) (let loop ((s 0) (k (A259934 (+ 1 n)))) (cond ((<= k t) s) ((= t (A049820 k)) (loop (+ s (A262697 k)) (- k 1))) (else (loop s (- k 1)))))))
%Y A262888 Cf. A000005, A049820, A082284, A259934, A262686, A262697, A262889, A262890, A262894.
%Y A262888 Cf. also A255328.
%K A262888 nonn
%O A262888 0,1
%A A262888 _Antti Karttunen_, Oct 04 2015