A214626 - OEIS

A214626

a(n) = (a(n-1) + a(n-3)) / gcd(a(n-1), a(n-3)) with a(0) = a(1) = 1 and a(2) = 3.

1, 1, 3, 4, 5, 8, 3, 8, 2, 5, 13, 15, 4, 17, 32, 9, 26, 29, 38, 32, 61, 99, 131, 192, 97, 228, 35, 132, 30, 13, 145, 35, 48, 193, 228, 23, 216, 37, 60, 23, 60, 2, 25, 17, 19, 44, 61, 80, 31, 92, 43, 74, 83, 126, 100, 183, 103, 203, 386, 489, 692, 539, 1028

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,3

COMMENTS

This sequence is to A179070 (without initial term) as A214551 is to A000930. - Reinhard Zumkeller, Jul 23 2012

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 0..10000

MATHEMATICA

RecurrenceTable[{a[n] == (a[n - 1] + a[n - 3])/GCD[a[n - 1], a[n - 3]], a[0] == 1, a[1] == 1, a[2] == 3}, a , {n, 0, 100}] (* G. C. Greubel, Apr 27 2017 *)

PROG

(Haskell)

a214626 n = a214626_list !! n

a214626_list = 1 : 1 : 3 : zipWith f a214626_list (drop 2 a214626_list)

where f u v = (u + v) `div` gcd u v

CROSSREFS

Cf. A214551, A179070, A000930, A214331, A214330, A214809.

Sequence in context: A365577 A325410 A269719 * A143593 A364089 A028267

Adjacent sequences: A214623 A214624 A214625 * A214627 A214628 A214629

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Jul 23 2012

STATUS

approved