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 A056865 #22 Mar 14 2025 12:58:46 %S A056865 0,0,0,0,1,2,3,4,6,8,10,12,14,16,19,22,25,28,32,36,40,44,48,52,57,62, %T A056865 67,72,78,84,90,96,102,108,115,122,129,136,144,152,160,168,176,184, %U A056865 193,202,211,220,230,240,250,260,270,280,291,302,313,324 %N A056865 a(n) = floor(n^2/10). %H A056865 Ray Chandler, <a href="/A056865/b056865.txt">Table of n, a(n) for n = 0..1000</a> %H A056865 <a href="/index/Rec#order_12">Index entries for linear recurrences with constant coefficients</a>, signature (2,-1,0,0,0,0,0,0,0,1,-2,1). %F A056865 G.f.: -x^4*(1+x^4) / ( (1+x)*(x^4-x^3+x^2-x+1)*(x^4+x^3+x^2+x+1)*(x-1)^3 ). - _R. J. Mathar_, Mar 08 2016 %p A056865 A056865 := proc(n) %p A056865 floor(n^2/10) ; %p A056865 end proc: %p A056865 seq(A056865(n),n=0..100) ; # _R. J. Mathar_, Mar 08 2016 %t A056865 Floor[Range[0,60]^2/10] (* or *) LinearRecurrence[{2,-1,0,0,0,0,0,0,0,1,-2,1},{0,0,0,0,1,2,3,4,6,8,10,12},60] (* _Harvey P. Dale_, Jun 29 2022 *) %o A056865 (PARI) a(n) = n^2\10; \\ _Michel Marcus_, Mar 08 2016 %Y A056865 Cf. A056864. %Y A056865 Cf. A000290, A007590, A000212, A002620, A118015, A056827, A056834, A130519, A056838. %K A056865 nonn,easy %O A056865 0,6 %A A056865 _N. J. A. Sloane_, Sep 02 2000