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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. 2
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 (list; graph; refs; listen; history; text; internal format)
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

A164901, A164922, A164923

Sequence in context: A067775 A140552 A138644 * A156830 A140556 A003627

Adjacent sequences:  A164918 A164919 A164920 * A164922 A164923 A164924

KEYWORD

nonn

AUTHOR

Leroy Quet, Aug 31 2009

EXTENSIONS

More terms. Sean A. Irvine, Sep 15 2009

STATUS

approved

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Last modified December 1 16:44 EST 2021. Contains 349430 sequences. (Running on oeis4.)