A125837 Numbers whose base 8 or octal representation is 6666666......6.

0, 6, 54, 438, 3510, 28086, 224694, 1797558, 14380470, 115043766, 920350134, 7362801078, 58902408630, 471219269046, 3769754152374, 30158033218998, 241264265751990, 1930114126015926, 15440913008127414, 123527304065019318, 988218432520154550, 7905747460161236406

Offset: 1

Author

Zerinvary Lajos, Feb 03 2007

Keywords

• nonn
• easy
• base

Links

• G. C. Greubel, Table of n, a(n) for n = 1..1000
• Index entries for linear recurrences with constant coefficients, signature (9,-8).

Crossrefs

Cf. A001018, A023001, A024088, A083068.

Programs

GAP

List([1..30], n-> 6*(8^(n-1)-1)/7); # G. C. Greubel, Aug 03 2019

Magma

[6*(8^(n-1)-1)/7: n in [1..30]]; // G. C. Greubel, Aug 03 2019

Maple

seq(6*(8^n-1)/7, n=0..30);

Mathematica

FromDigits[#,8]&/@Table[Table[6,{i}],{i,0,30}]  (* Harvey P. Dale, Mar 19 2011 *)
6*(8^(Range[30]-1) -1)/7 (* G. C. Greubel, Aug 03 2019 *)

PARI

vector(30, n, 6*(8^(n-1)-1)/7) \\ G. C. Greubel, Aug 03 2019

Sage

[6*(8^(n-1)-1)/7 for n in (1..30)] # G. C. Greubel, Aug 03 2019

Formula

a(n) = 6*(8^(n-1) -1)/7 = 6*A023001(n-1).

a(n) = 8*a(n-1) + 6 for n>1, a(1)=0. - Vincenzo Librandi, Oct 03 2010

G.f.: 6*x^2/( (1-x)*(1-8*x) ). - R. J. Mathar, Oct 07 2016

E.g.f.: 6*(exp(8*x) - exp(x))/7. - G. C. Greubel, Aug 03 2019

a(n) = -1 + A083068(n-1). - Alois P. Heinz, May 20 2023