1,2

Table of n, a(n) for n=1..72.

a(4) = 5 since 4 = 11[3] (i.e. written in base 2) and 5! = 11110[3] is the least factorial to have 11 as most significant digits in base 3.

(PARI) A155892(n)={ local( F=1, k=1 ); while( F\1!=n, F*=k++; while( F>=n+1, F/=3 )); k}

Cf. A155891, A018799, A076219.

Sequence in context: A264841 A191249 A005760 * A286480 A286256 A239111

Adjacent sequences: A155889 A155890 A155891 * A155893 A155894 A155895

base,nonn

M. F. Hasler, Feb 01 2009

approved