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 A048770 #22 Jul 02 2025 16:01:57
%S A048770 1,8,23,60,149,364,883,2136,5161,12464,30095,72660,175421,423508,
%T A048770 1022443,2468400,5959249,14386904,34733063,83853036,202439141,
%U A048770 488731324,1179901795,2848534920,6876971641,16602478208,40081928063
%N A048770 Partial sums of A048694.
%H A048770 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (3,-1,-1).
%F A048770 a(n) = ((7+4*sqrt(2))*(1+sqrt(2))^n-(7-4*sqrt(2))*(1-sqrt(2))^n)/(2*sqrt(2))-3.
%F A048770 a(n) = 2*a(n-1)+a(n-2)+6 with n>1, a(0)=1, a(1)=8.
%F A048770 a(n) = 3*a(n-1)-a(n-2)-a(n-3). G.f.: (1+5*x)/((1-x)*(1-2*x-x^2)). - _Colin Barker_, Jun 23 2012
%F A048770 a(n) = 3*A000129(n)+4*A000129(n+1)-3. - _R. J. Mathar_, Sep 27 2012
%t A048770 Accumulate[LinearRecurrence[{2,1},{1,7},40]] (* _Harvey P. Dale_, Jul 22 2011 *)
%t A048770 LinearRecurrence[{3, -1, -1},{1, 8, 23},27] (* _Ray Chandler_, Aug 03 2015 *)
%Y A048770 Cf. A001333, A000129, A048654, A048655, A048694.
%K A048770 nonn,easy,nice
%O A048770 0,2
%A A048770 _Barry E. Williams_
%E A048770 More terms from _James Sellers_, Jun 20 2000