login
A275873
a(n) = floor(r*a(n-1)) + floor(r*a(n-2)) + floor(r*a(n-3)), where r = 3/2, a(0) = a(1) = a(2) = 1.
1
1, 1, 1, 3, 6, 14, 34, 81, 193, 461, 1101, 2631, 6288, 15029, 35921, 85856, 205208, 490477, 1172311, 2801993, 6697170, 16007210, 38259559, 91445908, 218569015, 522411722, 1248639967, 2984431055, 7133224115, 17049442704, 40750646810, 97399970443, 232800089935
OFFSET
0,4
LINKS
FORMULA
a(n) = floor(r*a(n-1)) + floor(r*a(n-2)) + floor(r*a(n-3)), where r = 3/2, a(0) = a(1) = a(2) = 1.
MATHEMATICA
r = 3/2; a[0] = 1; a[1] = 1; a[2] = 1; z = 50;
a[n_] := a[n] = Floor[r*a[n - 1]] + Floor[r*a[n - 2]] + Floor[r*a[n - 3]];
t = Table[a[n], {n, 0, z}]
nxt[{a_, b_, c_}]:={b, c, Floor[(3a)/2]+Floor[(3b)/2]+Floor[(3c)/2]}; NestList[ nxt, {1, 1, 1}, 40][[All, 1]] (* Harvey P. Dale, Mar 13 2019 *)
CROSSREFS
Cf. A275862.
Sequence in context: A368983 A339600 A078062 * A018017 A184785 A350678
KEYWORD
easy,nonn
AUTHOR
Clark Kimberling, Aug 12 2016
STATUS
approved