cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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.

Original entry on oeis.org

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
Offset: 0

Views

Author

Reinhard Zumkeller, Jul 23 2012

Keywords

Comments

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

Crossrefs

Programs

  • 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
  • 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 *)