A134744 First differences of A084663.

2, 1, 1, 1, 1, 7, 1, 1, 1, 1, 1, 13, 1, 5, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 29, 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, 59, 3, 1, 1, 7, 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

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 simple prime-generating recurrence, arXiv:0710.3217 [math.NT], 2007-2008.

Crossrefs

Cf. A084663. See A106108 for other cross-references.

Cf. A132199, A134734, A134743.

Programs

Haskell

a134744 n = a134744_list !! (n-1)
a134744_list = zipWith (-) (tail a084663_list) a084663_list
-- Reinhard Zumkeller, Nov 15 2013

Mathematica

b[1] = 8; b[n_] := b[n] = b[n-1] + GCD[n, b[n-1]];
Table[b[n], {n, 105}] // Differences (* Jean-François Alcover, Sep 28 2018 *)