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 A261441 #11 Aug 20 2015 15:30:47 %S A261441 0,1,5,15,35,73,144,274,509,931,1685,3027,5409,9628,17088,30261,53497, %T A261441 94447,166563,293489,516772,909402,1599585,2812479,4943461,8686739, %U A261441 15261105,26806184,47077920,82669241,145152429,254839087,447378963,785340873,1378536968 %N A261441 Number of binary strings of length n+3 such that the smallest number whose binary representation is not visible in the string is 5. %H A261441 Alois P. Heinz, <a href="/A261441/b261441.txt">Table of n, a(n) for n = 0..1000</a> %H A261441 <a href="/index/Rec#order_08">Index entries for linear recurrences with constant coefficients</a>, signature (5,-10,12,-12,10,-6,3,-1). %F A261441 a(n) = A261019(n+3,5). %F A261441 G.f.: -(x^5+2*x^3-1)*x/((x^3-x^2+2*x-1)*(x^3+x-1)*(x-1)^2). - _Alois P. Heinz_, Aug 19 2015 %o A261441 (Haskell) %o A261441 a261441 0 = 0 %o A261441 a261441 n = a261019' (n + 3) 5 %Y A261441 Column k=5 of A261019. %K A261441 nonn,easy %O A261441 0,3 %A A261441 _Reinhard Zumkeller_, Aug 18 2015 %E A261441 More terms from _Alois P. Heinz_, Aug 19 2015