The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A028493 a(0) = 16, a(n+1) = 3a(n) - (6-n)^2. 0
 16, 12, 11, 17, 42, 122, 365, 1095, 3284, 9848, 29535, 88589, 265742, 797190, 2391521, 7174499, 21523416, 64570148, 193710323, 581130825, 1743392306, 5230176722, 15690529941, 47071589567, 141214768412 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 REFERENCES Seen in a newspaper quiz. LINKS Table of n, a(n) for n=0..24. FORMULA From Chai Wah Wu, Mar 29 2017: (Start) a(n) = 6*a(n-1) - 12*a(n-2) + 10*a(n-3) - 3*a(n-4) for n > 3. G.f.: (-65*x^3 + 131*x^2 - 84*x + 16)/((x - 1)^3*(3*x - 1)). (End) MAPLE (3^n + (5-n)*(6-n) + 1)/2; CROSSREFS Sequence in context: A008665 A076823 A070551 * A291426 A299524 A070534 Adjacent sequences: A028490 A028491 A028492 * A028494 A028495 A028496 KEYWORD nonn,easy AUTHOR Mark Orr (mjo(AT)cns.ed.ac.uk) EXTENSIONS Definition edited by Chai Wah Wu, Mar 29 2017 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified June 10 05:41 EDT 2023. Contains 363195 sequences. (Running on oeis4.)