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A216045 Numbers k such that Sum_{j=1..k-1} (4j)!/5^j is an integer. 5
1, 6, 30, 145, 151, 592, 732, 3895, 87806, 292432 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
Next term is > 1500000.
LINKS
MATHEMATICA
seq={}; sum=0; fak=1; k=0; While[k<10000, sum+=fak; If[Denominator[sum]==1, AppendTo[seq, k+1]]; k++; fak*=4*k*(4*k-1)*(4*k-2)*(4*k-3)/5; ]; seq
CROSSREFS
Sequence in context: A135160 A276022 A046945 * A307494 A316593 A089817
KEYWORD
nonn,more
AUTHOR
Vaclav Kotesovec, Aug 30 2012
STATUS
approved

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Last modified March 28 20:05 EDT 2024. Contains 371254 sequences. (Running on oeis4.)