This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A129005 (n^3+n^2)*5^n. 1
 0, 10, 300, 4500, 50000, 468750, 3937500, 30625000, 225000000, 1582031250, 10742187500, 70898437500, 457031250000, 2888183593750, 17944335937500, 109863281250000, 664062500000000, 3968811035156250, 23483276367187500 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS Vincenzo Librandi, Table of n, a(n) for n = 0..1000 Index to sequences with linear recurrences with constant coefficients, signature (20,-150,500,-625). FORMULA G.f.: 10*x*(1 + 10*x)/(1 - 5*x)^4. - Vincenzo Librandi, Feb 12 2013 a(n) = 20*a(n-1)-150*a(n-2)+500*a(n-3)-625*a(n-4). - Vincenzo Librandi, Feb 12 2013 a(n) = 10*A081143(n+2)+100*A081143(n+1). [Bruno Berselli, Feb 13 2013] MATHEMATICA CoefficientList[Series[10 x (1 + 10 x)/(1 - 5 x)^4, {x, 0, 30}], x] (* Vincenzo Librandi, Feb 12 2013 *) PROG (MAGMA) [(n^3+n^2)*5^n: n in [0..25]]; /* or */ I:=[0, 10, 300, 4500]; [n le 4 select I[n] else 20*Self(n-1)-150*Self(n-2)+500*Self(n-3)-625*Self(n-4): n in [1..25]]; // Vincenzo Librandi, Feb 12 2013 (PARI) A129005(n)=5^n*(1+n)*n^2 \\ - M. F. Hasler, Feb 12 2013 CROSSREFS Cf. A036289, A081143, A128796. Sequence in context: A173479 A173478 A069672 * A162729 A221953 A152165 Adjacent sequences:  A129002 A129003 A129004 * A129006 A129007 A129008 KEYWORD nonn,easy AUTHOR Mohammad K. Azarian, May 01 2007 EXTENSIONS Initial term a(0)=0 added by M. F. Hasler, Feb 12 2013 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .