A048335 a(n) in base 11 is a repdigit.

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 24, 36, 48, 60, 72, 84, 96, 108, 120, 133, 266, 399, 532, 665, 798, 931, 1064, 1197, 1330, 1464, 2928, 4392, 5856, 7320, 8784, 10248, 11712, 13176, 14640, 16105, 32210, 48315, 64420, 80525, 96630, 112735, 128840

Offset

0,3

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..1000

Eric Weisstein's World of Mathematics, Repdigit

Formula

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

a(n) = 12*a(n-10) - 11*a(n-20) for n > 19.

G.f.: x*(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)/(11*x^20 - 12*x^10 + 1). (End)

a(n) = (n - 10*floor((n-1)/10))*(11^floor((n+9)/10) - 1)/10. - Ilya Gutkovskiy, May 30 2016

Mathematica

Union[Flatten[Table[FromDigits[PadRight[{}, n, d], 11], {n, 0, 50}, {d, 10}]]] (* Vincenzo Librandi, Feb 06 2014 *)

Prog

(Python)
A048335_list = [0] + [int(d*l, 11) for l in range(1, 10) for d in '123456789a'] # Chai Wah Wu, May 30 2016

Crossrefs

Cf. A010785, A033024, A028987, A028988.

Sequence in context: A029956 A297274 A048322 * A068862 A061729 A286126

Adjacent sequences: A048332 A048333 A048334 * A048336 A048337 A048338

Keyword

nonn,base,easy

Author

Patrick De Geest, Feb 15 1999

Status

approved