This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A174316 #8 Sep 05 2025 15:18:38
%S A174316 1,1,1,2,6,10,18,34,66,130,258,514,1026,2050,4098,8194,16386,32770,
%T A174316 65538,131074,262146,524290,1048578,2097154,4194306,8388610,16777218,
%U A174316 33554434,67108866,134217730,268435458,536870914,1073741826,2147483650
%N A174316 Sequence defined by a(0)=a(1)=a(2)=1, a(3)=2, a(4)=6 and the formula a(n)=2^(n-2)+2 for n>=5.
%F A174316 G.f.: (1+x+x^2+2*x^3+6*x^4+((2*x^5)/(1-x))+((2*x)^5/(4*(1-2*x)))).
%F A174316 a(n) = A052548(n-2), n>3. - _R. J. Mathar_, Feb 29 2016
%e A174316 a(5)=2^3+2=10. a(6)=2^4+2=18.
%p A174316 taylor(((1+z^3+4*z^4-4*z^5)/(1-z))+((8*z^5)/(1-2*z)),z=0,50); v(0):=1:v(1):=1:v(2):=1:v(3):=2:v(4):=6: for n from 5 to 50 do v(n):=2^(n-2)+2:od:seq(v(n),n=0..50);
%t A174316 CoefficientList[Series[(1 + z + z^2 + 2*z^3 + 6*z^4 + ((2*z^5)/(1 - z)) + ((2*z)^5/(4*(1 - 2*z)))), {z, 0, 50}], z] (* _Wesley Ivan Hurt_, Sep 05 2025 *)
%Y A174316 Cf. A052548, A174314.
%K A174316 nonn,easy,changed
%O A174316 0,4
%A A174316 _Richard Choulet_, Mar 15 2010