A097328 - OEIS

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A097328

Denominator of 1 + 1/5 + 1/9 +...+ 1/(4n+1).

1, 5, 45, 585, 9945, 69615, 348075, 10094175, 111035925, 4108329225, 168441498225, 56147166075, 393030162525, 20830598613825, 395781373662675, 24142663793423175, 24142663793423175, 555281267248733025

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OFFSET

0,2

COMMENTS

The first 11 terms are the same as the least common multiples in A051539.

LINKS

Table of n, a(n) for n=0..17.

MATHEMATICA

Table[Denominator[Total[1/Range[1, 4n+1, 4]]], {n, 0, 20}]

CROSSREFS

Cf. A016813 (4n+1), A075136 (numerators), A051539 (lcm of 5, 9, 13, ..., 4n+1).

Sequence in context: A174495 A121414 A243678 * A051539 A007696 A090136

Adjacent sequences: A097325 A097326 A097327 * A097329 A097330 A097331

KEYWORD

easy,frac,nonn

AUTHOR

T. D. Noe, Aug 04 2004

STATUS

approved