A064854 a(n) = ((5^n mod 4^n) mod 3^n) mod 2^n.

1, 0, 7, 0, 21, 37, 118, 56, 19, 428, 808, 3920, 2256, 15240, 28312, 46733, 128931, 251439, 434788, 645833, 1397733, 1179155, 7185704, 1551886, 33308648, 65879944, 121274199, 65829274, 228529703, 248939750, 799831532, 2835988891, 1358930753, 9419331043, 9093076436

Offset: 1

Author

Labos Elemer, Oct 08 2001

Keywords

• nonn

Comments

A generalization of A002380 and A064536. It arises also as a coefficient (=c1) of 1^n=1 in a special (greedy) decomposition of 5^n into like powers as follows: 5^n = c4*4^n + c3*3^n + c2*2^n + c1*1^n.

Links

• Harry J. Smith, Table of n, a(n) for n = 1..200

Crossrefs

Cf. A002380, A064536, A064855, A060692, A064628-A064631.

Programs

PARI

a(n) = { ((5^n%4^n)%3^n)%2^n } \\ Harry J. Smith, Sep 28 2009

Formula

n = 7: 5^7 = 78125 = 4*16384 + 5*2187 + 12*128 + 118*1, where a(7)=118, the last coefficient.