login
A304431
a(n+1) = 1 + min( 2*a(floor(n/2)), 3*a(floor(n/3)) ), with a(0) = 0.
0
0, 1, 1, 1, 3, 3, 3, 3, 3, 4, 4, 4, 4, 7, 7, 7, 7, 7, 7, 9, 9, 9, 9, 9, 9, 9, 9, 10, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 21, 21, 22, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27
OFFSET
0,5
COMMENTS
Same recursion as Knuth numbers A007448 but different initial value.
PROG
(PARI) {a(n) = if( n<1, 0, n--; 1 + min( a(n\2)*2, a(n\3)*3 ))};
CROSSREFS
Cf. A007448.
Sequence in context: A176873 A227727 A050499 * A147752 A236682 A114227
KEYWORD
nonn
AUTHOR
Michael Somos, May 12 2018
STATUS
approved