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 A154992 #11 May 19 2024 14:45:00
%S A154992 0,0,1,5,17,53,161,485,1457,4373,13121,39365,118097,354293,1062881,
%T A154992 3188645,9565937,28697813,86093441,258280325,774840977,2324522933,
%U A154992 6973568801,20920706405,62762119217,188286357653,564859072961
%N A154992 A048473 prefixed by two zeros.
%C A154992 Consider two generic sequences correlated via c(n)=b(n) mod p. The difference d(n)=b(n)-c(n) contains only multiples of p and a(n)=d(n)/p defines another integer sequence. This sequence here takes b(n)=A048473(n) with p=9, such that c(n)=1,5,8,8,8,.. (period 8 continued). Then d(n)= 0,0,9,45,153,477,1449,.. becomes 9 times (two zeros followed by A048473) and division through 9 generates a(n) as the shifted version of b(n)=A048374(n).
%H A154992 G. C. Greubel, <a href="/A154992/b154992.txt">Table of n, a(n) for n = 0..1000</a>
%H A154992 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (4, -3).
%F A154992 a(n) = A048473(n-2) = 3*2^(n-2)-1, n>1. - _R. J. Mathar_, Jan 23 2009
%F A154992 G.f.: (x^3 + x^2)/(3*x^2 - 4*x + 1). - _Alexander R. Povolotsky_, Feb 21 2009
%t A154992 CoefficientList[Series[(x^3 + x^2)/(3*x^2 - 4*x + 1), {x, 0, 50}], x] (* _G. C. Greubel_, Feb 21 2017 *)
%t A154992 LinearRecurrence[{4,-3},{0,0,1,5},30] (* _Harvey P. Dale_, May 19 2024 *)
%o A154992 (PARI) x='x+O('x^50); Vec((x^3 + x^2)/(3*x^2 - 4*x + 1)) \\ _G. C. Greubel_, Feb 21 2017
%K A154992 nonn,less
%O A154992 0,4
%A A154992 _Paul Curtz_, Jan 18 2009
%E A154992 Edited and extended by _R. J. Mathar_, Jan 23 2009