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 A180234 #4 Jun 02 2025 03:03:06 %S A180234 0,0,2,1,1,2,2,2,3,3,4,5,6,7,9,11,13,16,20,24,30,37,45,56,69,85,105, %T A180234 129,159,196,242,298,368,454,560,691,852,1051,1297,1600,1974,2435, %U A180234 3004,3706,4572,5641,6959,8586,10593,13069,16124,19893,24543,30280,37358,46090 %N A180234 Demi-tribonacci numbers (rounding down): a(0)=a(1)=0, a(2)=2; a(n) = floor( (a(n-1)+a(n-2)+a(n-3))/2 ). %F A180234 a(0)=a(1)=0, a(2)=2; a(n) = floor( (a(n-1)+a(n-2)+a(n-3))/2 ) %F A180234 For n>9, a(n)=A180235(n-4)+1 %F A180234 a(n)/a(n-1) tends to 1.233751928528... which is a root of 2*x^3 - x^2 - x - 1 = 0 %Y A180234 Cf. A000213, A180235 %K A180234 easy,nonn %O A180234 0,3 %A A180234 _Carl R. White_, Aug 18 2010