A134743 First differences of A134736.

1, 3, 1, 5, 3, 1, 1, 1, 1, 11, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 23, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 47, 3, 1, 5, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 101, 3, 1, 1

Offset: 1

Author

N. J. A. Sloane, Jan 28 2008

Keywords

• nonn

References

• Eric S. Rowland, A simple prime-generating recurrence, Abstracts Amer. Math. Soc., 29 (No. 1, 2008), p. 50 (Abstract 1035-11-986).

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
• Eric S. Rowland, A natural prime-generating recurrence, arXiv:0710.3217 [math.NT], 2007-2008.

Crossrefs

See A106108 for other cross-references.

Cf. A134734, A134744.

Programs

Haskell

a134743 n = a134743_list !! (n-1)
a134743_list = zipWith (-) (tail a134736_list) a134736_list
-- Reinhard Zumkeller, Nov 15 2013

Mathematica

b[1] = 5; b[n_] := b[n] = b[n-1] + GCD[n, b[n-1]];
Array[b, 104] // Differences (* Jean-François Alcover, Oct 01 2018 *)

Formula

a(n) = A132199(n), n>2. [R. J. Mathar, Dec 13 2008]