login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Intersection of A264041 and A000217.
1

%I #4 Feb 01 2018 21:00:55

%S 1,3,6,10,21,36,55,78,105,136,171,210,253,300,351

%N Intersection of A264041 and A000217.

%F Conjectures (Start)

%F G.f.: x*(1 + 6*x^4 - 3*x^5) / (1 - x)^3.

%F a(n) = 6 - 7*n + 2*n^2 for n>3.

%F a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n>3.

%F (End)

%Y Cf. A000217, A264041.

%K nonn,more

%O 1,2

%A _Colin Barker_, Jan 31 2018