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1, 5, 350, 529200, 17542980000, 14783258730240000, 511420331138811494400000, 871980665589501641034301440000000, 60150685659205753788492548338089984000000000, 182771197941564481989784945231570147139911680000000000000
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OFFSET
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1,2
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COMMENTS
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Each term divides its successor, as in A203528. It is conjectured that each term is divisible by the corresponding superfactorial, A000178(n); as in A203529. See A093883 for a guide to related sequences.
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LINKS
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MAPLE
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b:= proc(n) option remember; local k; if n=1 then 1
else for k from 1+b(n-1) while isprime(k) do od; k fi
end:
a:= n-> mul(mul(b(i)+b(j), i=1..j-1), j=2..n):
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MATHEMATICA
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t = Table[If[PrimeQ[k], 0, k], {k, 1, 100}];
nonprime = Rest[Union[t]] (* A018252 *)
f[j_] := nonprime[[j]]; z = 20;
v[n_] := Product[Product[f[k] + f[j], {j, 1, k - 1}], {k, 2, n}]
d[n_] := Product[(i - 1)!, {i, 1, n}] (* A000178 *)
Table[v[n], {n, 1, z}] (* A203527 *)
Table[v[n + 1]/v[n], {n, 1, z - 1}] (* A203528 *)
Table[v[n]/d[n], {n, 1, 20}] (* A203529 *)
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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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STATUS
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approved
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