login
A155896
Least positive integer such that a(n)! starts with n, both written in base 6.
1
1, 2, 5, 4, 8, 3, 9, 26, 52, 18, 25, 10, 33, 53, 32, 15, 13, 20, 30, 5, 17, 42, 7, 4, 23, 43, 78, 50, 28, 113, 8, 44, 19, 334, 59, 100, 195, 27, 22, 14, 91, 172, 371, 16, 93, 9, 12, 102, 66, 26, 46, 95, 279, 303, 69, 331, 272, 52, 286, 79, 264, 298, 18, 21, 190, 104, 47, 138, 255
OFFSET
1,2
EXAMPLE
a(3) = 5 since 5!=120 is the least factorial to start with digit "3" when written in base 6. a(8) = 26 since 8 = 12[6] (i.e. written in base 6) and 26! is the smallest factorial to start with digits "12" when written in base 6.
PROG
(PARI) A155896(n)={ local( F=1, k=1 ); while( F\1!=n, F*=k++; while( F>=n+1, F/=6)); k}
CROSSREFS
KEYWORD
base,nonn
AUTHOR
M. F. Hasler, Feb 01 2009
STATUS
approved