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

1,2

Comments

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

Links

Table of n, a(n) for n=1..39.

Example

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.

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

Crossrefs

Cf. A085946.

Sequence in context: A124653 A365642 A353082 * A328444 A332301 A360281

Adjacent sequences: A085944 A085945 A085946 * A085948 A085949 A085950

Keyword

nonn,fini,full

Author

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

Extensions

More terms from David Wasserman, Feb 14 2005

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

Status

approved