A383325 Numbers not of the form round(3^k/5). Complement of A383324.
3, 4, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72
Offset: 1
Keywords
Crossrefs
Cf. A383324.
Programs
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Python
from sympy import integer_log def A383325(n): return (m:=n-1+(k:=integer_log(5*n+8,3)[0]+1))+(m>=(3**k+2)//5)
Formula
a(n) = m+1 if m >= floor((3^k+2)/5) and a(n) = m otherwise where k = floor(log_3(5*n+8))+1 and m = n-1+k.