A051063 27*n+9 or 27*n+18.

9, 18, 36, 45, 63, 72, 90, 99, 117, 126, 144, 153, 171, 180, 198, 207, 225, 234, 252, 261, 279, 288, 306, 315, 333, 342, 360, 369, 387, 396, 414, 423, 441, 450, 468, 477, 495, 504, 522, 531, 549, 558, 576, 585, 603, 612, 630, 639, 657, 666

Offset: 1

Author

N. J. A. Sloane, Gary W. Adamson

Keywords

• nonn
• easy

References

• Letter from Gary W. Adamson concerning Prouhet-Thue-Morse sequence, Nov. 11, 1999.

Links

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

Crossrefs

Equals 9*A001651(n).

Programs

Mathematica

LinearRecurrence[{1,1,-1},{9,18,36},60] (* Harvey P. Dale, Mar 09 2022 *)

Formula

a(n)=27*n-a(n-1) for n>0, a(0)=9. [Vincenzo Librandi, Aug 06 2010]

G.f. 9*x*( 1+x+x^2 ) / ( (1+x)*(x-1)^2 ). - R. J. Mathar, Sep 18 2013