A122148 - OEIS

A122148

Numerator of Sum[ (-1)^(k+1) * 1/p(k)^p(k), {k,1,n}], where p(k) = Prime[k].

1, 23, 71983, 59280758269, 16913492177093188294859, 5122675745984257357873512804013239827, 4237683625666802603266159755806379107958975382128522814879

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OFFSET

1,2

COMMENTS

C = Sum[ (-1)^(k+1) * 1/Prime[k]^Prime[k], {k,1,Infinity} ] = 1/2^2 - 1/3^3 + 1/5^5 - 1/7^7 + 1/11^11 - 1/13^13 + ... A122147[n] is a decimal expansion of C = 0.213281748700785698255627...

LINKS

Table of n, a(n) for n=1..7.

FORMULA

a(n) = Numerator[ Sum[ (-1)^(k+1) * 1/Prime[k]^Prime[k], {k,1,n} ] ].

EXAMPLE

a[n] / A076265[n] begins 1/4, 23/108, 71983/337500, ...

MATHEMATICA

Table[Numerator[Sum[(-1)^(k+1)*1/Prime[k]^Prime[k], {k, 1, n}]], {n, 1, 10}]

CROSSREFS

Cf. A051674, A122147, A094289, A117579, A076265, A000040.

Sequence in context: A173369 A185695 A101699 * A068736 A138763 A156176

Adjacent sequences: A122145 A122146 A122147 * A122149 A122150 A122151

KEYWORD

frac,nonn

AUTHOR

Alexander Adamchuk, Aug 22 2006

STATUS

approved