OFFSET
2,1
COMMENTS
a(n) expressed in base n is written with (n-1) ones followed by a zero. - Michel Marcus, Aug 25 2013
LINKS
Michael De Vlieger, Table of n, a(n) for n = 2..387
Tanya Khovanova and Gregory Marton, Archive Labeling Sequences, arXiv:2305.10357 [math.HO], 2023. See p. 9.
FORMULA
a(n) = Sum_{k=1..n-1} n^k.
a(n) = A023037(n) - 1, for n>1. - Michel Marcus, Aug 25 2013
MATHEMATICA
Array[(#^# - #)/(# - 1) &, 18, 2] (* Michael De Vlieger, May 24 2023 *)
PROG
(PARI) a(n)=(n^n-n)/(n-1)
(Python)
def A226238(n): return (n**n-n)//(n-1) # Chai Wah Wu, Sep 28 2023
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Ralf Stephan, Aug 25 2013
STATUS
approved