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A215021 a(n) = A118478(n)*(A118478(n)+1) divided by the product of the first n primes. 2
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,5

COMMENTS

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

LINKS

Table of n, a(n) for n=1..25.

CROSSREFS

Cf. A118478, A002110.

Sequence in context: A099939 A269231 A135734 * A215085 A241525 A321332

Adjacent sequences:  A215018 A215019 A215020 * A215022 A215023 A215024

KEYWORD

nonn

AUTHOR

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

EXTENSIONS

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

STATUS

approved

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Last modified May 6 16:17 EDT 2021. Contains 343586 sequences. (Running on oeis4.)