A064515 - OEIS

A064515

Write A064476(n) = 2^i(n)*3^j(n); sequence gives values of j(n).

0, 1, 1, 2, 2, 2, 3, 3, 3, 4, 3, 4, 4, 5, 4, 5, 4, 5, 6, 5, 6, 5, 6, 5, 7, 6, 7, 6, 7, 6, 8, 7, 6, 8, 7, 8, 7, 9, 8, 7, 9, 8, 7, 9, 8, 10, 9, 8, 10, 9, 8, 10, 9, 11, 8, 10, 9, 11, 10, 9, 11, 10, 12, 9, 11, 10, 12, 9, 11, 10, 12, 11, 13, 10, 12, 11, 13, 10, 12, 11, 13, 10, 12, 14, 11, 13, 12

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OFFSET

1,4

LINKS

Table of n, a(n) for n=1..87.

PROG

(ARIBAS) function a064515(maxarg: integer); var j: integer; ar: array; begin ar := p2p3(maxarg); for j := 0 to maxarg - 1 do write(ar[j][2], " "); end; end; a064515(95); (* For definition of function p2p3 see A064476. *)

(Python)

from sympy import integer_log

def A064515(n):

def bisection(f, kmin=0, kmax=1):

while f(kmax) > kmax: kmax <<= 1

kmin = kmax >> 1

while kmax-kmin > 1:

kmid = kmax+kmin>>1

if f(kmid) <= kmid:

kmax = kmid

else:

kmin = kmid

return kmax

def f(x): return n+x-sum(max(0, min((i<<1)+1, (x//3**i).bit_length())-i) for i in range(integer_log(x, 3)[0]+1))

return integer_log((m:=bisection(f, n, n))>>(m-1&~m).bit_length(), 3)[0] # Chai Wah Wu, Mar 26 2025

CROSSREFS

Cf. A064476, A064514.

Sequence in context: A080773 A134598 A325120 * A112754 A283467 A045864

Adjacent sequences: A064512 A064513 A064514 * A064516 A064517 A064518

KEYWORD

nonn,easy

AUTHOR

Vladeta Jovovic, Oct 07 2001, Oct 07 2001

EXTENSIONS

More terms from Klaus Brockhaus, Oct 12 2001

STATUS

approved