This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A086602 A000217(A000217(n))-n^2. 8
 0, 0, 2, 12, 39, 95, 195, 357, 602, 954, 1440, 2090, 2937, 4017, 5369, 7035, 9060, 11492, 14382, 17784, 21755, 26355, 31647, 37697, 44574, 52350, 61100, 70902, 81837, 93989, 107445, 122295, 138632, 156552, 176154, 197540, 220815, 246087 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS The sequence 2 12 39 95 195 ... can be decomposed as 1 5 14 30 55 ... A000330 plus 1 7 25 65 140 ... A001296. - Alford Arnold, Jun 29 2005 LINKS FORMULA a(n)=3*C(n+4,4)-C(n+2,2), n>= -2 . - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), May 02 2007 a(n)= 5*a(n-1) -10*a(n-2)+10*a(n-3) -5*a(n-4) +a(n-5) = n*(n-1)*(n^2+3*n-2)/8. G.f.: x^2*(-2-2*x+x^2)/(x-1)^5. [From R. J. Mathar, Oct 30 2009] EXAMPLE a(3)=t(t(3))-3^2=t(6)-9=21-9=12 MAPLE seq(3*binomial(n+4, 4)-binomial(n+2, 2), n=-2..35); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), May 02 2007 PROG (PARI) t(i)=i*(i+1)/2 w=vector(40, i, t(t(i))-i^2) CROSSREFS Cf. A000330, A001296. Sequence in context: A048349 A009632 A190022 * A019006 A168057 A008911 Adjacent sequences:  A086599 A086600 A086601 * A086603 A086604 A086605 KEYWORD nonn AUTHOR Jon Perry, Jul 23 2003 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 .

Last modified May 18 04:35 EDT 2013. Contains 225419 sequences.