A066992 Integers of the form C(2n,n)^2 * Sum_{i=1..n} 1/phi(i).

4, 72, 1000, 14700, 206388, 3201660, 46132944, 690153750, 8341753936986000, 127726170599795040, 1963050484817866410, 29928758453499691665, 466352632039095734625, 7143496319608441446500, 111027787209709780725315

Offset

1,1

Links

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

Crossrefs

Sequence in context: A119580 A209539 A139745 * A165212 A263219 A358295

Adjacent sequences: A066989 A066990 A066991 * A066993 A066994 A066995

Keyword

nonn

Author

Benoit Cloitre, Jan 27 2002

Extensions

Name corrected by Sean A. Irvine, Nov 27 2023

Status

approved