OFFSET
0,1
COMMENTS
Numbers k such that k^k ends with 9. - Bruno Berselli, Dec 11 2018
REFERENCES
Alfred S. Posamentier, Math Charmers, Tantalizing Tidbits for the Mind, Prometheus Books, NY, 2003, pp. 126-127.
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..5000
Tanya Khovanova, Recursive Sequences.
INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 979.
Index entries for linear recurrences with constant coefficients, signature (2,-1).
FORMULA
a(n) = 10*n + 9; a(n) = 2*a(n-1) - a(n-2). - Vincenzo Librandi, May 29 2011
G.f.: (9+x)/(x-1)^2. - R. J. Mathar, Oct 16 2015
From Elmo R. Oliveira, Apr 05 2025: (Start)
E.g.f.: exp(x)*(9 + 10*x).
a(n) = A016897(2*n+1). (End)
MATHEMATICA
Range[9, 1000, 10] (* Vladimir Joseph Stephan Orlovsky, May 28 2011 *)
PROG
(Magma) [10*n+9: n in [0..60]]; // Vincenzo Librandi, May 29 2011
(PARI) a(n)=10*n+9 \\ Charles R Greathouse IV, Feb 12 2017
(SageMath)
def A017377(n): return 10*n+9
print([A017377(n) for n in range(0, 54)]) # Stefano Spezia, May 26 2025
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved
