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.

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

Author

Antti Karttunen, May 13 2013

Keywords

• nonn

Comments

Row 3 of A225630.

This could be called a "thrice-iterated Landau's function."

Links

• Index entries for sequences related to lcm's

Crossrefs

Cf. A225630, A225627, A225629.

Programs

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))))))))