OFFSET
1,1
REFERENCES
Eric S. Rowland, A simple prime-generating recurrence, Abstracts Amer. Math. Soc., 29 (No. 1, 2008), p. 50 (Abstract 1035-11-986).
LINKS
T. D. Noe, Table of n, a(n) for n=1..1000
Eric S. Rowland, A natural prime-generating recurrence, arXiv:0710.3217 [math.NT], 2007-2008.
MATHEMATICA
a[1] = 5; a[n_] := a[n] = a[n-1] + GCD[n, a[n-1]];
Array[a, 66] (* Jean-François Alcover, Oct 01 2018 *)
RecurrenceTable[{a[1]==5, a[n]==a[n-1]+GCD[n, a[n-1]]}, a, {n, 70}] (* Harvey P. Dale, Nov 24 2018 *)
PROG
(Haskell)
a134736 n = a134736_list !! (n-1)
a134736_list =
5 : zipWith (+) a134736_list (zipWith gcd a134736_list [2..])
-- Reinhard Zumkeller, Nov 15 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Jan 28 2008
STATUS
approved