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A225628
a(n) = lcm(A225627(n),p1,p2,...,pk) for such a partition {p1+p2+...+pk} of n which maximizes this value among all partitions of n.
3
1, 1, 2, 6, 12, 60, 60, 420, 840, 1260, 840, 4620, 4620, 8580, 16380, 60060, 60060, 92820, 92820, 175560, 263340, 360360, 360360, 753480, 2762760, 6126120, 6126120, 8953560, 6846840, 13665960, 58198140, 58198140, 78738660, 78738660, 157477320, 157477320
OFFSET
0,3
COMMENTS
Row 3 of A225630.
This could be called a "thrice-iterated Landau's function."
PROG
(Scheme):
(define (A225628 n) (let ((maxlcm (list 0))) (fold_over_partitions_of n (A225627 n) lcm (lambda (p) (set-car! maxlcm (max (car maxlcm) p)))) (car maxlcm)))
;; Adapted by AK from Kreher & Stinson, CAGES-book, p. 68, Algorithm 3.1:
(define (fold_over_partitions_of m initval addpartfun colfun) (let recurse ((m m) (b m) (n 0) (partition initval)) (cond ((zero? m) (colfun partition)) (else (let loop ((i 1)) (recurse (- m i) i (+ 1 n) (addpartfun i partition)) (if (< i (min b m)) (loop (+ 1 i))))))))
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, May 13 2013
STATUS
approved