|
|
A120168
|
|
a(n) = 11 + floor(Sum_{j-1..n-1} a(j)/4).
|
|
3
|
|
|
11, 13, 17, 21, 26, 33, 41, 51, 64, 80, 100, 125, 156, 195, 244, 305, 381, 476, 595, 744, 930, 1163, 1453, 1817, 2271, 2839, 3548, 4435, 5544, 6930, 8663, 10828, 13535, 16919, 21149, 26436, 33045, 41306, 51633, 64541
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
LINKS
|
|
|
MATHEMATICA
|
f[n_, p_, q_]:= f[n, p, q]= p +Quotient[q +Sum[f[k, p, q], {k, n-1}], 4];
|
|
PROG
|
(Magma)
function f(n, a, b)
t:=0;
for k in [1..n-1] do
t+:= a+Floor((b+t)/4);
end for;
return t;
end function;
g:= func< n, a, b | f(n+1, a, b)-f(n, a, b) >;
(SageMath)
@CachedFunction
def f(n, p, q): return p + (q +sum(f(k, p, q) for k in range(1, n)))//4
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|