%I A036234
%S A036234 1,2,3,3,4,4,5,5,5,5,6,6,7,7,7,7,8,8,9,9,9,9,10,10,10,10,10,10,
%T A036234 11,11,12,12,12,12,12,12,13,13,13,13,14,14,15,15,15,15,16,16,16,
%U A036234 16,16,16,17,17,17,17,17,17,18,18,19,19,19,19,19,19,20,20,20,20
%N A036234 Number of primes <= n, if 1 is counted as a prime.
%C A036234 This sequence is the largest non-decreasing sequence a(n) such that a(Prime(n)-1) 
               = n. - Tanya Khovanova (tanyakh(AT)yahoo.com), Jun 20 2007
%C A036234 a(n) = partial sums of A080339(n) [characteristic function of {1} union 
               {primes}: 1 if n is 1 or a prime, else 0]. a(n) = A000720(n) + 1. 
               [From Jaroslav Krizek (jaroslav.krizek(AT)atlas.cz), Mar 23 2009]
%C A036234 Let G(n) be the graph whose vertices represent integers 1 through n, 
               and where vertices a and b are adjacent iff gcd(a,b)>1. Then a(n) 
               is the independence number of G(n). [From Aaron Dunigan AtLee (aaron(AT)duniganatlee.com), 
               May 23 2009]
%t A036234 Table[PrimePi[n] + 1, {n, 100}] - Tanya Khovanova (tanyakh(AT)yahoo.com), 
               Jun 20 2007
%Y A036234 Cf. A000720.
%Y A036234 Cf. A080339, A000720. [From Jaroslav Krizek (jaroslav.krizek(AT)atlas.cz), 
               Mar 23 2009]
%Y A036234 Sequence in context: A126236 A073047 A038567 this_sequence A061091 A086592 
               A132663
%Y A036234 Adjacent sequences: A036231 A036232 A036233 this_sequence A036235 A036236 
               A036237
%K A036234 nonn
%O A036234 1,2
%A A036234 N. J. A. Sloane (njas(AT)research.att.com).