A121205 "666" in bases 7 and higher rewritten in base 10.

342, 438, 546, 666, 798, 942, 1098, 1266, 1446, 1638, 1842, 2058, 2286, 2526, 2778, 3042, 3318, 3606, 3906, 4218, 4542, 4878, 5226, 5586, 5958, 6342, 6738, 7146, 7566, 7998, 8442, 8898, 9366, 9846, 10338, 10842, 11358, 11886, 12426

Offset

7,1

Links

Table of n, a(n) for n=7..45.

Index entries for linear recurrences with constant coefficients, signature (3,-3,1).

Formula

a(n) = 6*(n^2 + n + 1) = a(n-1) + 12*n.

Example

In octal notation "666" means 6*8*8 + 6*8 + 6 = 438.

Mathematica

Table[FromDigits[{6, 6, 6}, n], {n, 7, 50}] (* or *) LinearRecurrence[{3, -3, 1}, {342, 438, 546}, 40] (* Harvey P. Dale, Apr 15 2018 *)

Prog

(PARI) a(n) = 6*(n^2 + n + 1); \\ Michel Marcus, Aug 20 2013

Crossrefs

Sequence in context: A247441 A045106 A137201 * A038852 A043419 A252243

Adjacent sequences: A121202 A121203 A121204 * A121206 A121207 A121208

Keyword

easy,nonn

Author

Axel Harvey, Aug 19 2006

Extensions

More terms from Michel Marcus, Aug 20 2013

Status

approved