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!)
A226200 6^n + n. 5
1, 7, 38, 219, 1300, 7781, 46662, 279943, 1679624, 10077705, 60466186, 362797067, 2176782348, 13060694029, 78364164110, 470184984591, 2821109907472, 16926659444753, 101559956668434, 609359740010515, 3656158440062996, 21936950640377877, 131621703842267158 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

After 7, the next prime of this form has 238 digits. - Bruno Berselli, Jun 18 2013

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..300

Index entries for linear recurrences with constant coefficients, signature (8,-13,6).

FORMULA

G.f.: (-1+x+5*x^2)/((6*x-1)*(x-1)^2).

a(n) = 8*a(n-1)-13*a(n-2)+6*a(n-3).

MATHEMATICA

Table[6^n + n, {n, 0, 30}] (* or *) CoefficientList[Series[(-1 + x + 5 x^2) / ((6 x - 1) (x - 1)^2), {x, 0, 30}], x]

PROG

(MAGMA) [6^n+n: n in [0..30]]; /* or */ I:=[1, 7, 38]; [n le 3 select I[n] else 8*Self(n-1)-13*Self(n-2)+6*Self(n-3): n in [1..30]];

(PARI) a(n)=6^n+n \\ Charles R Greathouse IV, Oct 07 2015

CROSSREFS

Cf. numbers of the form k^n+n: A006127 (k=2), A104743 (k=3), A158879 (k=4), A104745 (k=5), this sequence (k=6), A226199 (k=7), A226201 (k=8), A226202 (k=9), A081552 (k=10), A226737 (k=11).

Cf. A199320 (first differences).

Sequence in context: A104553 A027241 A292761 * A056197 A229126 A158576

Adjacent sequences:  A226197 A226198 A226199 * A226201 A226202 A226203

KEYWORD

nonn,easy

AUTHOR

Vincenzo Librandi, Jun 16 2013

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 16:24 EST 2019. Contains 329808 sequences. (Running on oeis4.)