A139222 a(n) = 30*n - 27.

3, 33, 63, 93, 123, 153, 183, 213, 243, 273, 303, 333, 363, 393, 423, 453, 483, 513, 543, 573, 603, 633, 663, 693, 723, 753, 783, 813, 843, 873, 903, 933, 963, 993, 1023, 1053, 1083, 1113, 1143, 1173, 1203, 1233, 1263, 1293, 1323, 1353, 1383, 1413, 1443, 1473

Offset: 1

Author

Odimar Fabeny, Jun 06 2008

Keywords

• nonn
• easy

Comments

Multiples of 3 with the units digit equal to 3.

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..2000
• Index entries for linear recurrences with constant coefficients, signature (2,-1).

Crossrefs

Subsequence of A034709, together with A017281, A017293, A139245, A017329, A139249, A139264, A139279 and A139280.

Programs

Magma

[30*n - 27: n in [1..60]]; // Vincenzo Librandi, Jun 17 2011

Mathematica

Range[3, 2000, 30] (* Vladimir Joseph Stephan Orlovsky, Jun 15 2011 *)
30*Range[50]-27 (* or *) NestList[30+#&,3,50] (* Harvey P. Dale, Mar 27 2021 *)

PARI

a(n)=30*n-27 \\ Charles R Greathouse IV, Aug 25 2014

Formula

a(n) = a(n-1) + 30.

From Elmo R. Oliveira, Apr 04 2025: (Start)

G.f.: 3*x*(1+9*x)/(1-x)^2.

E.g.f.: 3*(exp(x)*(10*x - 9) + 9).

a(n) = 3*A017281(n-1) = A139280(n)/3.

a(n) = 2*a(n-1) - a(n-2) for n > 2. (End)

Extensions

More terms from Reinhard Zumkeller, Jun 22 2008