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.

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, 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, 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

Offset: 0

Author

Antti Karttunen, Oct 04 2015

Keywords

• nonn

Links

• Antti Karttunen, Table of n, a(n) for n = 0..8107

Crossrefs

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

Cf. also A255328.

Programs

Scheme

(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)))))))

Formula

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

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

Other identities. For all n >= 0:

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