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 A097926 #11 Jun 06 2022 12:22:17
%S A097926 18,36,70,134,258,498,960,1850,3566,6874,13250,25540,49230,94894,
%T A097926 182914,352578,679616,1310002,2525110,4867306,9382034,18084452,
%U A097926 34858902,67192694,129518082,249654130,481223808,927588714,1787984734,3446451386
%N A097926 Number of (n,4) Freiman-Wyner sequences.
%C A097926 "The values for n <= 4 are straightforward."
%D A097926 I. F. Blake, The enumeration of certain run length sequences, Information and Control, 55 (1982), 222-237.
%H A097926 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (1,1,1,1).
%F A097926 a(n) = 2a(n-1) - a(n-k-1), k=4, n >= 2k+2. - _R. J. Mathar_, Oct 31 2006
%F A097926 G.f.: -2*(5*x^3+8*x^2+9*x+9)*x^5/(x^4+x^3+x^2+x-1) = -10*x^4-6*x^3-2*x^2-2+(-2*x^3-2+2*x)/(x^4+x^3+x^2+x-1). - _R. J. Mathar_, Nov 18 2007
%p A097926 A097926 := proc(nmax) local a,n,k; k := 4 ; a := [18,36,70,134,258] ; while nops(a) < nmax do n := nops(a)+k+1 ; a := [op(a),2*op(n-1-k,a)-op(n-2*k-1,a) ] ; od ; end: nmax := 30 ; a := A097926(nmax) ; for i from 1 to nmax do printf("%d,",op(i,a)) ; od: # _R. J. Mathar_, Oct 31 2006
%t A097926 LinearRecurrence[{1,1,1,1},{18,36,70,134},30] (* _Harvey P. Dale_, Jun 06 2022 *)
%Y A097926 Cf. A006355, A097925.
%K A097926 nonn
%O A097926 5,1
%A A097926 _N. J. A. Sloane_, Sep 05 2004
%E A097926 Corrected and extended by _R. J. Mathar_, Oct 31 2006