login
This site is supported by donations to The OEIS Foundation.

 

Logo

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!)
A014827 a(1)=1, a(n) = 5*a(n-1) + n. 11
1, 7, 38, 194, 975, 4881, 24412, 122068, 610349, 3051755, 15258786, 76293942, 381469723, 1907348629, 9536743160, 47683715816, 238418579097, 1192092895503, 5960464477534, 29802322387690, 149011611938471 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Index entries for linear recurrences with constant coefficients, signature (7,-11,5).

FORMULA

a(n) = (5^(n+1) - 4*n - 5)/16.

G.f.: x/((1-5*x)*(1-x)^2).

a(n) = Sum_{k=0..n} (n-k)*5^k = Sum_{k=0..n} k*5^(n-k). - Paul Barry, Jul 30 2004

a(n) = Sum_{k=0..n} binomial(n+2, k+2)*4^k [Offset 0]. - Paul Barry, Jul 30 2004

MAPLE

a:=n->sum((5^(n-j)-1^(n-j))/4, j=0..n): seq(a(n), n=1..21); # Zerinvary Lajos, Jan 04 2007

MATHEMATICA

Join[{a=1, b=7}, Table[c=6*b-5*a+1; a=b; b=c, {n, 60}]] (* Vladimir Joseph Stephan Orlovsky, Feb 06 2011 *)

PROG

(Sage) [(gaussian_binomial(n, 1, 5)-n)/4 for n in xrange(2, 23)] # Zerinvary Lajos, May 29 2009

(MAGMA) [(5^(n+1)-4*n-5)/16: n in [1..30]]; // Vincenzo Librandi, Aug 23 2011

CROSSREFS

Cf. A016218, A016208, A000392, A000225, A003462, A003463, A003464, A023000, A023001, A002452, A002275, A016123, A016125, A016256.

Sequence in context: A037605 A128726 A055146 * A141845 A048437 A099461

Adjacent sequences:  A014824 A014825 A014826 * A014828 A014829 A014830

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane

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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 6 14:15 EST 2019. Contains 329806 sequences. (Running on oeis4.)