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A186720 As p runs through the primes, sequence gives denominator of Sum_{k=1..p-1} 1/k^2. 2
1, 4, 144, 3600, 1270080, 153679680, 519437318400, 150117385017600, 221193371393280, 6450247552370862240000, 5424658191543895143840000, 20852386088294732932920960000, 28546916554875489385168794240000, 6855338104106528236638391873920000, 12675520154492970709544386574878080000 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..15.

R. Mestrovic, Wolstenholme's theorem: Its Generalizations and Extensions in the last hundred and fifty years (1862-2011), arXiv:1111.3057, 2011

MAPLE

f2:=proc(n) local p;

p:=ithprime(n);

denom(add(1/i^2, i=1..p-1));

end proc;

[seq(f2(n), n=1..20)];

CROSSREFS

Cf. A125551, A061002.

Sequence in context: A134631 A036511 A263386 * A060870 A268894 A084703

Adjacent sequences:  A186717 A186718 A186719 * A186721 A186722 A186723

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Jan 21 2012

STATUS

approved

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Last modified March 28 21:25 EDT 2017. Contains 284246 sequences.