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Search: id:A068788
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| A068788 |
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S(n; 1,3) = S(n; 3,3) where S(n; t,s) is the number of length n 4-ary strings whose digits sum to t mod 4 and whose sum of products of all pairs of digits sum to s mod 4. |
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+0 10
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OFFSET
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1,3
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LINKS
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F. Ruskey, 4-ary strings with given trace and subtrace.
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FORMULA
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S(n; t, s) = S(n-1; t, s) + S(n-1; t+3, s+3t+1) + S(n-1; t+2, s+2t) + S(n-1; t+1, s+t+1)
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CROSSREFS
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Cf. A073953, A068711, A073955, A068777, A068786, A068778, A073959, A068789, A073962.
Adjacent sequences: A068785 A068786 A068787 this_sequence A068789 A068790 A068791
Sequence in context: A002713 A009318 A081682 this_sequence A094013 A106568 A075581
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KEYWORD
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nonn
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AUTHOR
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Frank Ruskey (fruskey(AT)cs.uvic.ca), Mar 29 2002
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