%I A130130
%S A130130 0,1,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
%T A130130 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
%U A130130 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2
%N A130130 a(0)=0, a(1)=1, a(n)=2 for n >= 2.
%C A130130 a(n) = number of obvious divisors of n. The obvious divisors of n are 
               the numbers 1 and n. [From Jaroslav Krizek (jaroslav.krizek(AT)atlas.cz), 
               Mar 02 2009]
%C A130130 Number of colors needed to paint n adjacent segments on a line. [From 
               Jaume Oliver Lafont (joliverlafont(AT)gmail.com), Mar 20 2009]
%F A130130 a(n)=2*[(n+2) mod (n+1)]-[n!^2 mod (n+1)]*[(n+1)!^2 mod (n+2)], with 
               n>=0. - Paolo P. Lava (ppl(AT)spl.at), Aug 28 2007
%F A130130 G.f.: x*(1+x)/(1-x)=x*(1-x^2)/(1-x)^2 [From Jaume Oliver Lafont (joliverlafont(AT)gmail.com), 
               Mar 20 2009]
%Y A130130 Cf. A158411. [From Jaume Oliver Lafont (joliverlafont(AT)gmail.com), 
               Mar 20 2009]
%Y A130130 Sequence in context: A077433 A065685 A084100 this_sequence A046698 A036453 
               A040000
%Y A130130 Adjacent sequences: A130127 A130128 A130129 this_sequence A130131 A130132 
               A130133
%K A130130 nonn
%O A130130 0,3
%A A130130 Paul Curtz (bpcrtz(AT)free.fr), Aug 01 2007