A381255 Positive integers not of the form round(2^(k+2)/5). Complement of A007910.

4, 5, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74

Offset

1,1

Links

Table of n, a(n) for n=1..67.

Formula

a(n) = m+1 if m>=floor((2^k+2)/5) otherwise a(n) = m where k = floor(log_2(5*n+3))+1 and m = n-2+k.

Prog

(Python)
def A381255(n): return (m:=n-2+(k:=(5*n+3).bit_length()))+(m>=((1<<k)|2)//5)

Crossrefs

Cf. A007910.

Sequence in context: A196001 A257542 A182757 * A164515 A298871 A298874

Adjacent sequences: A381252 A381253 A381254 * A381256 A381257 A381258

Keyword

nonn

Author

Chai Wah Wu, Apr 21 2025

Status

approved