%I #17 Sep 28 2018 18:46:07
%S 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,
%T 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,
%U 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
%N First differences of A084663.
%D Eric S. Rowland, A simple prime-generating recurrence, Abstracts Amer. Math. Soc., 29 (No. 1, 2008), p. 50 (Abstract 1035-11-986).
%H Reinhard Zumkeller, <a href="/A134744/b134744.txt">Table of n, a(n) for n = 1..10000</a>
%H Eric S. Rowland, <a href="http://arXiv.org/abs/0710.3217">A simple prime-generating recurrence</a>, arXiv:0710.3217 [math.NT], 2007-2008.
%t b[1] = 8; b[n_] := b[n] = b[n-1] + GCD[n, b[n-1]];
%t Table[b[n], {n, 105}] // Differences (* _Jean-François Alcover_, Sep 28 2018 *)
%o (Haskell)
%o a134744 n = a134744_list !! (n-1)
%o a134744_list = zipWith (-) (tail a084663_list) a084663_list
%o -- _Reinhard Zumkeller_, Nov 15 2013
%Y Cf. A084663. See A106108 for other cross-references.
%Y Cf. A132199, A134734, A134743.
%K nonn
%O 1,1
%A _N. J. A. Sloane_, Jan 28 2008