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A055227
Nearest integer to sqrt( n! ).
2
1, 1, 1, 2, 5, 11, 27, 71, 201, 602, 1905, 6318, 21886, 78911, 295260, 1143536, 4574144, 18859677, 80014834, 348776577, 1559776269, 7147792818, 33526120082, 160785623545, 787685471323, 3938427356615, 20082117944246, 104349745809074, 552166953567228
OFFSET
0,4
FORMULA
a(n) = A000194(A000142(n)).
MATHEMATICA
Round[Sqrt[Range[0, 30]!]] (* Harvey P. Dale, Aug 27 2013 *)
PROG
(Python)
from gmpy2 import isqrt
A055227_list, g = [1], 1
for i in range(1, 101):
....g *= i
....s = isqrt(g)
....A055227_list.append(int(s if g-s*(s+1) <= 0 else s+1)) # Chai Wah Wu, Jul 24 2015
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Henry Bottomley, Jun 21 2000
STATUS
approved