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

Author

Axel Harvey, Aug 19 2006

Keywords

• easy
• nonn

Examples

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

Links

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

Programs

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 *)

PARI

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

Formula

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

Extensions

More terms from Michel Marcus, Aug 20 2013