login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A332159 a(n) = 5*(10^(2*n+1)-1)/9 + 4*10^n. 9
9, 595, 55955, 5559555, 555595555, 55555955555, 5555559555555, 555555595555555, 55555555955555555, 5555555559555555555, 555555555595555555555, 55555555555955555555555, 5555555555559555555555555, 555555555555595555555555555, 55555555555555955555555555555, 5555555555555559555555555555555 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

Table of n, a(n) for n=0..15.

Index entries for linear recurrences with constant coefficients, signature (111,-1110,1000).

FORMULA

a(n) = 5*A138148(n) + 9*10^n = A002279(2n+1) + 4*10^n.

G.f.: (9 - 404*x - 100*x^2)/((1 - x)(1 - 10*x)(1 - 100*x)).

a(n) = 111*a(n-1) - 1110*a(n-2) + 1000*a(n-3) for n > 2.

MAPLE

A332159 := n -> 5*(10^(2*n+1)-1)/9+4*10^n;

MATHEMATICA

Array[5 (10^(2 # + 1)-1)/9 + 4*10^# &, 15, 0]

PROG

(PARI) apply( {A332159(n)=10^(n*2+1)\9*5+4*10^n}, [0..15])

(Python) def A332159(n): return 10**(n*2+1)//9*5+4*10**n

CROSSREFS

Cf. A002275 (repunits R_n = (10^n-1)/9), A002279 (5*R_n), A011557 (10^n).

Cf. A138148 (cyclops numbers with binary digits), A002113 (palindromes).

Cf. A332119 .. A332189 (variants with different repeated digit 1, ..., 8).

Cf. A332150 .. A332159 (variants with different middle digit 0, ..., 9).

Sequence in context: A061611 A238609 A015092 * A139107 A226552 A277232

Adjacent sequences:  A332156 A332157 A332158 * A332160 A332161 A332162

KEYWORD

nonn,base,easy

AUTHOR

M. F. Hasler, Feb 09 2020

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 September 24 03:15 EDT 2021. Contains 347623 sequences. (Running on oeis4.)