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A163913
Number of integers i in range [A000302(n-1)..A024036(n)] of permutation A163355/A163356 with A163915(i)=i, but not A163355(i)=i.
3
0, 0, 6, 3, 30, 27, 162, 171, 885, 987, 4839, 5502, 26436, 30216
OFFSET
0,3
PROG
(MIT Scheme:)
(define (A163913 n) (let ((rp (range-of-n-th-quaternary-forest n))) (let loop ((s 0) (i (car rp))) (cond ((> i (cdr rp)) s) ((and (not (= (A163355 i) i)) (= (A163915 i) i)) (loop (1+ s) (1+ i))) (else (loop s (1+ i)))))))
(define (range-of-n-th-quaternary-forest n) (if (zero? n) (cons n n) (cons (A000302 (-1+ n)) (+ (A000302 (-1+ n)) (-1+ (A002001 n))))))
CROSSREFS
a(n) = 3*A163914(n). See also A163903.
Sequence in context: A286174 A282076 A282553 * A022666 A202363 A038257
KEYWORD
nonn
AUTHOR
Antti Karttunen, Sep 19 2009
STATUS
approved