A048337 a(n) in base 13 is a repdigit.

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 28, 42, 56, 70, 84, 98, 112, 126, 140, 154, 168, 183, 366, 549, 732, 915, 1098, 1281, 1464, 1647, 1830, 2013, 2196, 2380, 4760, 7140, 9520, 11900, 14280, 16660, 19040, 21420, 23800, 26180, 28560, 30941, 61882

Offset

0,3

Comments

Integers n such that A043540(n)=1. - Michel Marcus, Aug 19 2015

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..1200

Eric Weisstein's World of Mathematics, Repdigit

Formula

From Chai Wah Wu, May 30 2016: (Start)

a(n) = 14*a(n-12) - 13*a(n-24) for n > 23.

G.f.: x*(12*x^11 + 11*x^10 + 10*x^9 + 9*x^8 + 8*x^7 + 7*x^6 + 6*x^5 + 5*x^4 + 4*x^3 + 3*x^2 + 2*x + 1)/(13*x^24 - 14*x^12 + 1). (End)

a(n) = (n - 12*floor((n-1)/12))*(13^floor((n+11)/12) - 1)/12. - Ilya Gutkovskiy, May 30 2016

Mathematica

Union[Flatten[Table[FromDigits[PadRight[{}, n, d], 13], {n, 0, 50}, {d, 12}]]] (* Vincenzo Librandi, Feb 06 2014 *)

Prog

(PARI) isok(n) = !n || (#vecsort(digits(n, 13), , 8) == 1) \\ Michel Marcus, Aug 19 2015
(Python)
A048337_list = [0] + [int(d*l, 13) for l in range(1, 10) for d in '123456789abc'] # Chai Wah Wu, May 30 2016

Crossrefs

Cf. A010785, A033026, A028987, A028988, A043540.

Sequence in context: A029958 A297280 A048324 * A003964 A023781 A135578

Adjacent sequences: A048334 A048335 A048336 * A048338 A048339 A048340

Keyword

nonn,base,easy

Author

Patrick De Geest, Feb 15 1999

Status

approved