OFFSET
1,1
COMMENTS
a(n) - a(n-1) is in {2,3,4} for n >= 1; also, 3n - a(n) is in {0, 1} for n >= 1. The first 20 numbers 3n - a(n) are 0, 1, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, with 1 in positions given by A287420.
LINKS
Clark Kimberling, Table of n, a(n) for n = 1..10000
MATHEMATICA
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, May 26 2017
STATUS
approved