login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Partial sums of A006000.
1

%I #14 Apr 21 2024 22:04:00

%S 1,5,17,45,100,196,350,582,915,1375,1991,2795,3822,5110,6700,8636,

%T 10965,13737,17005,20825,25256,30360,36202,42850,50375,58851,68355,

%U 78967,90770,103850,118296,134200,151657,170765,191625,214341,239020,265772

%N Partial sums of A006000.

%C Prime for a(1) = 5, a(2) = 17, then never again?

%H <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (5,-10,10,-5,1).

%F a(n) = Sum_{i=0..n} A006000(i).

%F a(n) = Sum_{i=0..n} (i+1)*(i^2+i+2)/2.

%F a(n) = ((n^4+2*n^3+n^2)/4+(2*n^3+3*n^2+n)/3+(3*n^2+3*n)/2+2*n)/2+1.

%F G.f.: -(2*x^2 + 1) / (x-1)^5. - _Colin Barker_, Apr 28 2013

%F a(n) = (n+1)*(n+2)*(3*n^2+5*n+12)/24. - _Alois P. Heinz_, Apr 28 2013

%F a(n) = 5*a(n-1)-10*a(n-2)+10*a(n-3)-5*a(n-4)+a(n-5). - _Wesley Ivan Hurt_, Apr 21 2024

%t LinearRecurrence[{5,-10,10,-5,1},{1,5,17,45,100},40] (* _Harvey P. Dale_, Sep 15 2022 *)

%Y Cf. A006000.

%K easy,nonn

%O 0,2

%A _Jonathan Vos Post_, Dec 19 2007