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 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. 5

%I

%S 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 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 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 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 Antti Karttunen, <a href="/A262888/b262888.txt">Table of n, a(n) for n = 0..8107</a>

%F a(n) = sum_{k = A082284(A259934(n)) .. A259934(n+1)} [A049820(k) = A259934(n)] * A262697(k).

%F (Here [ ] stands for Iverson bracket, giving as its result 1 only when A049820(k) = A259934(n), and 0 otherwise).

%F Other identities. For all n >= 0:

%F A262890(n) = a(n) + A262889(n).

%o (Scheme)

%o (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 Cf. A000005, A049820, A082284, A259934, A262686, A262697, A262889, A262890, A262894.

%Y Cf. also A255328.

%K nonn

%O 0,1

%A _Antti Karttunen_, Oct 04 2015

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Last modified September 30 22:26 EDT 2020. Contains 337440 sequences. (Running on oeis4.)