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1, 2, 4, 26, 18, 482, 266, 6050, 3114, 21122, 10730, 22178, 11226, 4455362, 2256338, 343874, 173610, 13643522, 6869842, 690621122, 347772738, 16250361602, 8187307306, 17146915106, 8584448890, 720152334722, 365024665978, 59381983394, 29700003082
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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0,2
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LINKS
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FORMULA
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MAPLE
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A053657 := proc(n) local P, p, q, s, r;
P := select(isprime, [$2..n]); r:=1;
for p in P do s := 0; q := p-1;
do if q > (n-1) then break fi;
s := s + iquo(n-1, q); q := q*p; od;
r := r * p^s; od; r end:
# Row sums:
seq (a(n), n = 0..22);
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MATHEMATICA
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b[n_] := b[n] = Product[p^Sum[Floor[(n-1)/((p-1) p^k)], {k, 0, n}], {p, Prime[ Range[n]]}];
T[n_, k_] := b[n]/(b[k] b[n-k]);
a[n_] := Sum[T[n, k], {k, 0, n}];
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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