This site is supported by donations to The OEIS Foundation.

 Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing. Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A014831 a(1)=1; for n>1, a(n) = 8*a(n-1)+n. 5
 1, 10, 83, 668, 5349, 42798, 342391, 2739136, 21913097, 175304786, 1402438299, 11219506404, 89756051245, 718048409974, 5744387279807, 45955098238472, 367640785907793, 2941126287262362, 23529010298098915, 188232082384791340, 1505856659078330741 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS FORMULA a(n) = (8^(n+1)-7*n-8)/49. - Rolf Pleisch, Oct 21 2010 a(n) = Sum_{i=0..n-1} 7^i*binomial(n+1,n-1-i). [Bruno Berselli, Nov 13 2015] EXAMPLE For n=5, a(5) = 1*15 + 7*20 + 7^2*15 + 7^3*6 + 7^4*1 = 5349. [Bruno Berselli, Nov 13 2015] MAPLE a:=n->sum((8^(n-j)-1)/7, j=0..n): seq(a(n), n=1..19); # Zerinvary Lajos, Jan 15 2007 a:= n-> (Matrix ([[1, 0, 1], [1, 1, 1], [0, 0, 8]])^n)[2, 3]: seq (a(n), n=1..25); # Alois P. Heinz, Aug 06 2008 MATHEMATICA Table[(8^(n + 1) - 7 n - 8)/49, {n, 1, 25}] (* Bruno Berselli, Nov 13 2015 *) CROSSREFS Cf. A000420, A104712. Sequence in context: A037699 A037608 A055149 * A048440 A226202 A271557 Adjacent sequences:  A014828 A014829 A014830 * A014832 A014833 A014834 KEYWORD nonn,easy AUTHOR STATUS approved

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

Last modified December 8 18:37 EST 2019. Contains 329865 sequences. (Running on oeis4.)