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A039952
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Maximum cardinality of finite D0L sequence over an alphabet with n symbols.
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2
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1, 2, 3, 4, 5, 6, 7, 12, 15, 20, 30, 31, 60, 61, 84, 105, 140, 210, 211, 420, 421, 422, 423, 840, 841, 1260, 1261, 1540, 2310, 2520, 4620, 4621, 5460, 5461, 9240, 9241, 13860, 13861, 16380, 16381, 27720, 30030, 32760, 60060, 60061, 60062, 60063, 120120, 120121
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OFFSET
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0,2
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REFERENCES
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P. M. B. Vitanyi, Lindenmayer Systems: Structure, Languages and Growth Functions, Mathematisch Centrum, Math. Centre Tracts #96, 1980, p. 25.
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LINKS
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FORMULA
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Max { Prod p^a + d : Sum p^a + d = n }, p prime.
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EXAMPLE
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a(11) = 31 because we can write 11 = 1 + 2 + 3 + 5 and 31 = 1+2*3*5.
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PROG
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(PARI) \\ here s is A051703 as a vector
s(n)={my(v=vector(n+1)); v[1]=1; forprime(p=2, n, forstep(i=#v, 1, -1, my(q=1); while(q*p<i, q*=p; v[i]=max(v[i], q*v[i-q])))); v}
seq(n)={my(v=s(n)); for(i=2, #v, v[i]=max(v[i], v[i-1]+1)); v} \\ Andrew Howroyd, Jan 05 2018
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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First 4 values appear incorrectly in cited references; corrected by JOS
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STATUS
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approved
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