OFFSET
0,3
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..300
FORMULA
a(0)=1, a(n) = a(n-1)*floor(sqrt(2*n)+1/2) for n>0. - Alois P. Heinz, May 20 2013
MAPLE
a:= proc(n) option remember; `if`(n=0, 1,
a(n-1) * floor(sqrt(2*n)+1/2))
end:
seq(a(n), n=0..30); # Alois P. Heinz, May 20 2013
MATHEMATICA
t = Table[n, {n, 9}, {n}] // Flatten; b[n_] := t[[n]]; a[0] = 1; a[n_] := a[n] = b[n] a[n-1]; Table[a[n], {n, 0, t // Length}] (* Jean-François Alcover, Feb 21 2016 *)
PROG
(PARI) lista(nn) = my(na = 1, i = 0, im = 1, list=List()); listput(list, na); while (i < nn, for (j=1, im, na *= im; listput(list, na); i++; ); im++; ); Vec(list); \\ Michel Marcus, May 20 2013; Jun 19 2025
(Python)
from math import isqrt, comb, prod
def A010552(n): return (a:=(m:=isqrt(k:=n<<1))+(k>m*(m+1)))**(n-comb(a, 2))*prod(i**i for i in range(2, a)) # Chai Wah Wu, Jun 19 2025
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved
