A286178 - OEIS

A286178

Denominator of Sum_{i=1..n}(A285388(i)*A285389(i+1))/(A285388(i+1)*A285389(i)).

35, 255255, 100280245065, 2152114239059719935, 1952792905443446363385953865, 40347439369046572433179287578305731225, 772786810821609466400679930812513688804332910188025, 73222791895598040395939625423986137213129917738912050041051075

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OFFSET

1,1

COMMENTS

Conjecture: the factorization of a(n) contains all primes 5 < p < 2*(n+1)^2.

LINKS

Table of n, a(n) for n=1..8.

MATHEMATICA

a388[i_] := Numerator[2^(1 - 2 i^2) i Binomial[2 i^2, i^2]]; a389[i_] := Denominator[2^(1 - 2 i^2) i Binomial[2 i^2, i^2]]; Denominator[Table[Sum[(a388[i]/a389[i])/((a388[i + 1]/a389[i + 1])), {i, 1, n}], {n, 1, 10}]]

CROSSREFS

Cf. A285388, A285389, A286179 (numerators).

Sequence in context: A212926 A139473 A110596 * A126029 A107736 A261121

Adjacent sequences: A286175 A286176 A286177 * A286179 A286180 A286181

KEYWORD

nonn,frac

AUTHOR

Ralf Steiner, May 04 2017

STATUS

approved