# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a115565 Showing 1-1 of 1 %I A115565 #25 Sep 08 2022 08:45:24 %S A115565 11,61,281,911,2311,4961,9461,16531,27011,41861,62161,89111,124031, %T A115565 168361,223661,291611,374011,472781,589961,727711,888311,1074161, %U A115565 1287781,1531811,1809011,2122261,2474561,2869031,3308911,3797561,4338461,4935211,5591531 %N A115565 a(n) = 5*n^4 - 10*n^3 + 20*n^2 - 15*n + 11. %H A115565 Vincenzo Librandi, Table of n, a(n) for n = 1..10000 %H A115565 Index entries for linear recurrences with constant coefficients, signature (5, -10, 10, -5, 1). %F A115565 a(1-n) = a(n) = 5*(n^2-n)^2 +15*(n^2-n) +11. - _Michael Somos_, May 15 2006 %F A115565 a(1)=11, a(2)=61, a(3)=281, a(4)=911, a(5)=2311, a(n)=5*a(n-1)-10*a(n-2)+ 10*a(n-3)-5*a(n-4)+a(n-5). - _Harvey P. Dale_, Oct 03 2011 %F A115565 G.f.: x*(11+6*x+86*x^2+6*x^3+11*x^4)/(1-x)^5. - _Wesley Ivan Hurt_, Aug 22 2015 %p A115565 A115565:=n->5*n^4 - 10*n^3 + 20*n^2 - 15*n + 11: seq(A115565(n), n=1..40); # _Wesley Ivan Hurt_, Aug 22 2015 %t A115565 Table[5n^4-10n^3+20n^2-15n+11,{n,40}] (* or *) LinearRecurrence[ {5,-10,10,-5,1},{11,61,281,911,2311},40] (* _Harvey P. Dale_, Oct 03 2011 *) %t A115565 CoefficientList[Series[(11 + 6 x + 86 x^2 + 6 x^3 + 11 x^4)/(1 - x)^5, {x, 0, 40}], x] (* _Wesley Ivan Hurt_, Aug 22 2015 *) %o A115565 ay1[1] := 11; a[1] :=50; b[1] :=170; c[1] :=240; k := 120; Repeat ay1[1] := ay1[1] + a[1]; a[1] := a[1] + b[1]; b[1] := b[1] + c[1]; c[1] := c[1] + k; writeln(ay1[1]); Until 1 < 0; %o A115565 (Magma) [5*(n^2-n)^2 +15*(n^2-n) +11: n in [1..40]]; // _Vincenzo Librandi_, Oct 04 2011 %o A115565 (PARI) a(n) = 5*n^4 - 10*n^3 + 20*n^2 - 15*n + 11 \\ _Charles R Greathouse IV_, Aug 22 2015 %o A115565 (PARI) first(m)=vector(m,i,5*i^4 - 10*i^3 + 20*i^2 - 15*i + 11) \\ _Anders Hellström_, Aug 22 2015 %K A115565 nonn,easy %O A115565 1,1 %A A115565 Aldrich Stevens (Aldrichstevens(AT)msn.com), Mar 11 2006 %E A115565 Checked by _N. J. A. Sloane_, Mar 29 2006 %E A115565 Edited by _N. J. A. Sloane_, Jun 13 2008 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE