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 A138995 #13 Dec 22 2018 12:04:53 %S A138995 1,1,6,2,2,10,3,3,14,4,4,18,5,5,22,6,6,26,7,7,30,8,8,34,9,9,38,10,10, %T A138995 42,11,11,46,12,12,50,13,13,54,14,14,58,15,15,62,16,16,66,17,17,70,18, %U A138995 18,74,19,19,78,20,20,82,21,21,86,22,22,90,23,23,94,24,24,98,25,25,102,26 %N A138995 First differences of Frobenius numbers for 4 successive numbers A138984. %C A138995 For first differences of Frobenius numbers for 2 successive numbers see A005843 %C A138995 For first differences of Frobenius numbers for 3 successive numbers see A014682 %C A138995 For first differences of Frobenius numbers for 4 successive numbers see A138995 %C A138995 For first differences of Frobenius numbers for 5 successive numbers see A138996 %C A138995 For first differences of Frobenius numbers for 6 successive numbers see A138997 %C A138995 For first differences of Frobenius numbers for 7 successive numbers see A138998 %C A138995 For first differences of Frobenius numbers for 8 successive numbers see A138999 %H A138995 G. C. Greubel, <a href="/A138995/b138995.txt">Table of n, a(n) for n = 1..1000</a> %H A138995 <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,2,0,0,-1). %F A138995 a(n) = A138984(n+1) - A138984(n). %F A138995 a(n) = 2*a(n-3) - a(n-6). - R. J. Mathar, Apr 20 2008 %F A138995 a(n) = (1/3)*x(mod(n,3))*mod(n,3)-(1/3)*n*x(mod(n,3))+(1/3)*n*x(3+mod(n,3))+x(mod(n,3))-(1/3)*mod(n,3)*x(3+mod(n,3)). - _Alexander R. Povolotsky_, Apr 20 2008 %F A138995 G.f.: -x*(2*x^5-6*x^2-x-1) / ((x-1)^2*(x^2+x+1)^2). - _Colin Barker_, Dec 13 2012 %t A138995 a = {}; Do[AppendTo[a, FrobeniusNumber[{n + 1, n + 2, n + 3, n + 4}]], {n, 1, 100}]; Differences[a] %t A138995 LinearRecurrence[{0, 0, 2, 0, 0, -1}, {1, 1, 6, 2, 2, 10},50] (* _G. C. Greubel_, Feb 18 2017 *) %t A138995 Differences[Table[FrobeniusNumber[Range[n,n+3]],{n,2,100}]] (* _Harvey P. Dale_, Dec 22 2018 *) %o A138995 (PARI) x='x+O('x^50); Vec(-x*(2*x^5-6*x^2-x-1) / ((x-1)^2*(x^2+x+1)^2)) \\ _G. C. Greubel_, Feb 18 2017 %Y A138995 Cf. A028387, A037165, A079326, A138985, A138986, A138987, A138988, A138989, A138990, A138991, A138992, A138993, A138994, A138995, A138996, A138997, A138998, A138999. %K A138995 nonn,easy %O A138995 1,3 %A A138995 _Artur Jasinski_, Apr 05 2008