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 A298469 #6 Apr 11 2018 09:03:40 %S A298469 1,3,17,21,25,29,33,37,41,45,49,53,57,61,66,73,77,82,89,93,98,105,109, %T A298469 114,121,125,130,137,141,146,153,157,162,169,173,178,185,189,194,201, %U A298469 205,210,217,221,226,233,237,242,249,253,257 %N A298469 a(n) = a(0)*b(n) + a(1)*b(n-1), where a(0) = 1, a(1) = 3, b(0) = 2; b(1) = 4 ; b(2) = 5. %C A298469 The increasing complementary sequences a() and b() are uniquely determined by the titular equation and initial values. See A297830 for a guide to related sequences. %H A298469 Clark Kimberling, <a href="/A298469/b298469.txt">Table of n, a(n) for n = 0..1000</a> %e A298469 a(2) = 1*5 + 3*4 = 17. %t A298469 mex[list_, start_] := (NestWhile[# + 1 &, start, MemberQ[list, #] &]); %t A298469 aCoeffs = {1, 3}; bCoeffs = {2, 4, 5}; %t A298469 Table[a[n - 1] = #[[n]], {n, Length[#]}] &[aCoeffs]; %t A298469 Table[b[n - 1] = #[[n]], {n, Length[#]}] &[bCoeffs]; %t A298469 a[n_] := Hold[Sum[a[z] b[n - z], {z, 0, Length[aCoeffs] - 1}]] %t A298469 Table[{a[z] = ReleaseHold[a[z]], b[z + 1] = %t A298469 mex[Join[Table[a[n], {n, 0, z}], Table[b[n], {n, 0, z}]], 1]}, {z, %t A298469 Length[aCoeffs], 1000}]; %t A298469 Table[a[n], {n, 0, 50}] (* A298469 *) %t A298469 Table[b[n], {n, 0, 50}] (* complement *) %t A298469 (* _Peter J. C. Moses_, Jan 19 2018 *) %Y A298469 Cf. A298338, A298295. %K A298469 nonn,easy %O A298469 0,2 %A A298469 _Clark Kimberling_, Feb 11 2018