OFFSET
1,1
COMMENTS
Previous name was: 3 people at a party are saying Hello to each other. Person 2 says Hello Hello. Person 3 counts the times Hello has been said and says Hello thrice that number of times. Person 1 says Hello a number of times equal to the sum of Hello's and then it is Person 2's turn again. This is the total number of Hello's said.
LINKS
FORMULA
G.f.: 2*x*(1+4*x+8*x^2)/(1-24*x^3). - Colin Barker, Jun 07 2012
a(n) = 2^n*b(n-1) where b(n) = 1, 2, 2, 3, 6, 6, 9, 18, 18, 27, 54, ... (n >= 0) is A038754 with each 2nd term repeated. - R. J. Mathar, May 21 2018
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Jon Perry, Oct 15 2002
STATUS
approved