A025545 a(n) = (1/4 + 1/6 + ... + 1/c(n))*LCM{4, 6, ..., c(n)}, where c(n) = n-th composite number.

1, 5, 13, 47, 271, 301, 2287, 2455, 5225, 5505, 5757, 5997, 68487, 70797, 365073, 4884549, 15054047, 15440147, 15800507, 32276689, 32931889, 570652913, 581154833, 591365033, 11419719227, 11598790427, 11773384847, 11939665247, 12098387447, 12253582487

Offset

1,2

Links

Table of n, a(n) for n=1..30.

Crossrefs

Sequence in context: A120790 A162563 A250133 * A146152 A082132 A220900

Adjacent sequences: A025542 A025543 A025544 * A025546 A025547 A025548

Keyword

nonn

Author

Clark Kimberling

Status

approved