A068944 Highest power of 9 dividing A068943(n) for n>0.

0, 0, 0, 2, 7, 28, 108, 414, 1585, 6087, 23446, 90532, 350343, 1358437, 5276545, 20527950, 79976007, 311984922, 1218474389, 4763911699, 18643889114, 73029856058, 286302435505, 1123267533520, 4410123312095, 17326303720537

Offset

1,4

Comments

Sequence was suggested by the discovery that the digital root of A068943 is 9 for all n>3.

Links

Table of n, a(n) for n=1..26.

Example

a(11)=23446 since f(11,11,11)=9^binomial(12,10) * 6^binomial(15,10) * 3^(18,10) * other terms. this implies a(11)=binomial(12,10) + 1/2*(binomial(15,10)-1 + binomial(18,10)).

Crossrefs

Cf. A068943, A068945.

Sequence in context: A092465 A099488 A289607 * A215143 A289158 A012855

Adjacent sequences: A068941 A068942 A068943 * A068945 A068946 A068947

Keyword

nonn

Author

Francois Jooste (phukraut(AT)hotmail.com), Mar 09 2002

Status

approved