OFFSET
1,1
COMMENTS
This is the sequence of numbers congruent to 19 mod 40.
A142190 gives the primes in this sequence.
LINKS
Karl V. Keller, Jr., Table of n, a(n) for n = 1..10000
Tanya Khovanova, Recursive Sequences
Index entries for linear recurrences with constant coefficients, signature (2,-1).
FORMULA
G.f.: x*(19+21*x)/(1-x)^2. - Vincenzo Librandi, Nov 11 2014
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3). - Vincenzo Librandi, Nov 11 2014
MATHEMATICA
40 Range[40] - 21 (* Alonso del Arte, Nov 10 2014 *)
CoefficientList[Series[(19 + 21 x) / (1 - x)^2, {x, 0, 50}], x] (* Vincenzo Librandi, Nov 11 2014 *)
PROG
(Python) for n in range(1, 101): print(40*n-21, end=", ")
(Magma) [40*n-21: n in [1..60]]; // Vincenzo Librandi, Nov 11 2014
(PARI) a(n)=40*n-21 \\ Charles R Greathouse IV, May 23 2019
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Karl V. Keller, Jr., Nov 10 2014
STATUS
approved