login
This site is supported by donations to The OEIS Foundation.

 

Logo

Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing.
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A138995 First differences of Frobenius numbers for 4 successive numbers A138984. 5

%I

%S 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 42,11,11,46,12,12,50,13,13,54,14,14,58,15,15,62,16,16,66,17,17,70,18,

%U 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 First differences of Frobenius numbers for 4 successive numbers A138984.

%C For first differences of Frobenius numbers for 2 successive numbers see A005843

%C For first differences of Frobenius numbers for 3 successive numbers see A014682

%C For first differences of Frobenius numbers for 4 successive numbers see A138995

%C For first differences of Frobenius numbers for 5 successive numbers see A138996

%C For first differences of Frobenius numbers for 6 successive numbers see A138997

%C For first differences of Frobenius numbers for 7 successive numbers see A138998

%C For first differences of Frobenius numbers for 8 successive numbers see A138999

%H G. C. Greubel, <a href="/A138995/b138995.txt">Table of n, a(n) for n = 1..1000</a>

%H <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,2,0,0,-1).

%F a(n) = A138984(n+1) - A138984(n).

%F a(n) = 2*a(n-3) - a(n-6). - R. J. Mathar, Apr 20 2008

%F 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 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 a = {}; Do[AppendTo[a, FrobeniusNumber[{n + 1, n + 2, n + 3, n + 4}]], {n, 1, 100}]; Differences[a]

%t LinearRecurrence[{0, 0, 2, 0, 0, -1}, {1, 1, 6, 2, 2, 10},50] (* _G. C. Greubel_, Feb 18 2017 *)

%t Differences[Table[FrobeniusNumber[Range[n,n+3]],{n,2,100}]] (* _Harvey P. Dale_, Dec 22 2018 *)

%o (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 Cf. A028387, A037165, A079326, A138985, A138986, A138987, A138988, A138989, A138990, A138991, A138992, A138993, A138994, A138995, A138996, A138997, A138998, A138999.

%K nonn,easy

%O 1,3

%A _Artur Jasinski_, Apr 05 2008

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 9 17:18 EST 2019. Contains 329879 sequences. (Running on oeis4.)