A085947 a(1) = 1, a(2) = 2 and a(n) = smallest number not included earlier that divides the sum of the two previous terms.

1, 2, 3, 5, 4, 9, 13, 11, 6, 17, 23, 8, 31, 39, 7, 46, 53, 33, 43, 19, 62, 27, 89, 29, 59, 22, 81, 103, 92, 15, 107, 61, 12, 73, 85, 79, 41, 10, 51

Offset: 1

Author

Amarnath Murthy and Meenakshi Srikanth (menakan_s(AT)yahoo.com), Jul 14 2003

Keywords

• nonn
• fini
• full

Comments

The next term would have to divide 61, but 1 and 61 are both already used. - Franklin T. Adams-Watters, Oct 23 2015

Examples

			After 46 and 53 the term is 33 and not 1,3,9 or 11 as they have already been included. 33 divides 46+53 = 99.
		

Crossrefs

Cf. A085946.

Programs

Maple

a[1]:= 1:
a[2]:= 2:
for n from 3 do
  r:= min(numtheory:-divisors(a[n-1]+a[n-2]) minus {seq(a[i],i=1..n-1)});
  if r = infinity then break fi;
  a[n]:= r
od:
seq(a[i],i=1..n-1); # Robert Israel, Oct 25 2015

Extensions

More terms from David Wasserman, Feb 14 2005

Name corrected by Franklin T. Adams-Watters, Oct 23 2015