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A167280
Period length 12: 0,0,1,2,4,7,4,8,7,4,8,5 (and repeat).
0
0, 0, 1, 2, 4, 7, 4, 8, 7, 4, 8, 5, 0, 0, 1, 2, 4, 7, 4, 8, 7, 4, 8, 5, 0, 0, 1, 2, 4, 7, 4, 8, 7, 4, 8, 5, 0, 0, 1, 2, 4, 7, 4, 8, 7, 4, 8, 5, 0, 0, 1, 2, 4, 7, 4, 8, 7, 4, 8, 5, 0, 0, 1, 2, 4, 7, 4, 8, 7, 4, 8, 5, 0, 0, 1, 2, 4, 7, 4, 8, 7, 4, 8, 5, 0, 0, 1, 2, 4, 7, 4, 8, 7, 4, 8, 5, 0, 0, 1, 2, 4, 7, 4, 8, 7
OFFSET
0,4
COMMENTS
The sum of the terms in the period is 50, so the partial sums of the sequence are also 12-periodic if reduced modulo 50 or modulo 10.
The weighted partial sums b(n) = sum_{i=0..n} a(i)*2^i obey b(n) = b(n+12) (mod 10).
Third column is A000689. (Which table or array is this referring to? R. J. Mathar, Nov 01 2009)
The set of digits in the period is the same as in A141425.
A derived sequence with terms a(n)+a(n+6) has period length 6: 4, 8, 8, 6, 12, 12 (repeat).
FORMULA
a(n) = A113405(n+1) mod 10.
G.f.: x^2*(1+2*x+4*x^2+7*x^3+4*x^4+8*x^5+7*x^6+4*x^7+8*x^8+5*x^9)/( (1-x)*(1+x+x^2)*(1+x)*(1-x+x^2)*(1+x^2)*(x^4-x^2+1)) [R. J. Mathar, Nov 03 2009]
CROSSREFS
Sequence in context: A074958 A222407 A230724 * A236629 A019966 A021408
KEYWORD
nonn,easy
AUTHOR
Paul Curtz, Nov 01 2009
EXTENSIONS
Edited by R. J. Mathar, Nov 05 2009
STATUS
approved