A164921 a(1)=0, a(2)=1. For n >=3, a(n) = the smallest integer > a(n-1) that is coprime to every sum of any two distinct earlier terms of this sequence.

0, 1, 2, 5, 11, 17, 23, 29, 37, 41, 47, 53, 59, 67, 71, 79, 83, 89, 97, 101, 107, 113, 127, 131, 137, 149, 157, 163, 167, 173, 179, 191, 197, 211, 223, 227, 233, 239, 251, 257, 263, 269, 277, 281, 293, 307, 311, 317, 331, 337, 347, 353, 359, 367, 373, 379, 383

Offset

1,3

Links

Table of n, a(n) for n=1..57.

Example

The first 4 terms are 0,1,2,5. The sums of every pair of distinct terms are: 0+1=1, 0+2=2, 1+2=3, 0+5=5, 1+5=6, and 2+5=7. So we are looking for the smallest integer >5 that is coprime to 1, 2, 3, 5, 6, and 7. This number, which is a(5), is 11.

Crossrefs

Cf. A164901, A164922, A164923.

Sequence in context: A140552 A138644 A350314 * A156830 A140556 A003627

Adjacent sequences: A164918 A164919 A164920 * A164922 A164923 A164924

Keyword

nonn

Author

Leroy Quet, Aug 31 2009

Extensions

More terms from Sean A. Irvine, Sep 15 2009

Status

approved