login
This site is supported by donations to The OEIS Foundation.

 

Logo

Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing.
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A277326 LCM of nonzero coefficients of the n-th Stern polynomial. 6
1, 1, 1, 1, 1, 2, 1, 1, 1, 2, 2, 3, 1, 2, 1, 1, 1, 2, 2, 3, 2, 12, 3, 6, 1, 6, 2, 3, 1, 2, 1, 1, 1, 2, 2, 6, 2, 20, 3, 12, 2, 4, 12, 30, 3, 20, 6, 6, 1, 6, 6, 15, 2, 60, 3, 12, 1, 6, 2, 3, 1, 2, 1, 1, 1, 2, 2, 6, 2, 60, 6, 12, 2, 12, 20, 40, 3, 140, 12, 12, 2, 12, 4, 40, 12, 60, 30, 140, 3, 60, 20, 40, 6, 20, 6, 6, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,6

COMMENTS

a(n) = the least common multiple of nonzero terms on the n-th row of A125184.

LINKS

Antti Karttunen, Table of n, a(n) for n = 0..8192

Index entries for sequences related to lcm's

FORMULA

a(n) = A072411(A260443(n)).

a(2n) = a(n).

a(n) <= A277325(n).

PROG

(Scheme)

(define (A277326 n) (A072411 (A260443 n)))

;; A standalone implementation:

(define (A277326 n) (reduce lcm 1 (filter positive? (A260443as_coeff_list n))))

(definec (A260443as_coeff_list n) (cond ((zero? n) (list)) ((= 1 n) (list 1)) ((even? n) (cons 0 (A260443as_coeff_list (/ n 2)))) (else (add_two_lists (A260443as_coeff_list (/ (- n 1) 2)) (A260443as_coeff_list (/ (+ n 1) 2))))))

(define (add_two_lists nums1 nums2) (let ((len1 (length nums1)) (len2 (length nums2))) (cond ((< len1 len2) (add_two_lists nums2 nums1)) (else (map + nums1 (append nums2 (make-list (- len1 len2) 0)))))))

CROSSREFS

Cf. A072411, A125184, A260443.

Differs from A277325 for the first time at n=13, where a(13) = 2, while A277325(13) = 4.

After n=0, differs from A277315 for the first time at n=21, where a(21) = 12, while A277315(21) = 4.

Sequence in context: A262561 A264990 A277315 * A050431 A051574 A029386

Adjacent sequences:  A277323 A277324 A277325 * A277327 A277328 A277329

KEYWORD

nonn

AUTHOR

Antti Karttunen, Oct 13 2016

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 8 01:59 EST 2019. Contains 329850 sequences. (Running on oeis4.)