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 A195116 #23 Sep 08 2022 08:45:59 %S A195116 12,25,77,319,1577,8575,48977,286759,1699817,10137775,60645377, %T A195116 363332599,2178384857,13065493375,78378545777,470228096839, %U A195116 2821239178697,16927047127375,101561119454177,609363227843479,3656168902513337,21936982025631775 %N A195116 a(n) = (2+3^n)*(3+2^n). %H A195116 Bruno Berselli, <a href="/A195116/b195116.txt">Table of n, a(n) for n = 0..1000</a> %H A195116 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (12,-47,72,-36). %F A195116 G.f.: (12-119*x+341*x^2-294*x^3)/((1-x)*(1-2*x)*(1-3*x)*(1-6*x)). %F A195116 Sum_{i=0..n} a(i) = (1/10)*(12*6^n+45*3^n+40*2^n+60*n+23). %t A195116 Table[(2 + 3^n) (3 + 2^n), {n, 0, 30}] (* _Vincenzo Librandi_, Mar 26 2013 *) %o A195116 (Magma) [(2+3^n)*(3+2^n): n in [0..21]]; %o A195116 (PARI) for(n=0, 21, print1((2+3^n)*(3+2^n)", ")); %o A195116 (Python) %o A195116 def a(n): return (2+3**n)*(3+2**n) %o A195116 print([a(n) for n in range(23)]) # _Michael S. Branicky_, Dec 25 2021 %Y A195116 Cf. A060013 ((1+2^n)*(2+1) with n>3). %Y A195116 Cf. A021029 (for the recurrence). %K A195116 nonn,easy %O A195116 0,1 %A A195116 _Bruno Berselli_, Sep 09 2011