A215021 a(n) = A118478(n)*(A118478(n)+1) divided by the product of the first n primes.

1, 1, 1, 1, 19, 17, 1, 409, 604, 82, 20951, 229931, 411012, 39080794, 4382914408, 6345486566, 45119290746, 581075656330, 8672770990, 869561574799171, 71853663603175593, 25509154378676494, 24040267482771436703, 102403319155457392955, 11302410854347731819765

Offset: 1

Author

N. J. A. Sloane, Aug 02 2012, following a comment in A118478 made by Robert G. Wilson v on May 13 2006

Keywords

• nonn

Comments

When floor(A214089(n) / 2) = A118478(n), a(n) = A215085(n).

Links

• Chai Wah Wu, Table of n, a(n) for n = 1..31

Crossrefs

Cf. A118478, A002110.

Extensions

a(18)-a(25) from J. Stauduhar, Aug 17 2012