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URL: https://oeis.org/A073274

⇱ A073274 - OEIS


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A073274
a(n) = A000040(n+1) - A073273(n).
3
0, 1, 0, 2, 0, 2, 0, 0, 3, -1, 2, 2, 0, 0, 1, 3, -1, 2, 2, -1, 2, 0, 0, 3, 2, 0, 2, 0, -4, 6, 0, 3, -3, 5, -1, 1, 2, 0, 1, 3, -3, 5, 0, 2, -4, 1, 5, 2, 0, 0, 3, -3, 3, 1, 1, 3, -1, 2, 2, -3, -1, 6, 2, 0, -4, 5, -1, 5, 0, 0, 0, 2, 1, 2, 0, 0, 3, -1, 0, 5, -3, 5, -1, 2, 0, 0, 3, 2, 0, -3, 3, 3, -1, 3
OFFSET
1,4
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
EXAMPLE
For n=11, A000040(11)*A000040(13) = 31*41 = 1271 = 35*35+46, therefore A073273(11)=35; a(11) = A000040(12)-A073273(11) = 37-35 = +2.
PROG
(PARI) vector(94, n, prime(n+1) - sqrtint(prime(n)*prime(n+2))) \\ Michel Marcus, Jun 02 2015
(PARI) a(n, p=prime(n))=my(q=nextprime(p+1), r=nextprime(q+1)); q - sqrtint(p*r) \\ Charles R Greathouse IV, Jun 02 2015
CROSSREFS
KEYWORD
sign
AUTHOR
Reinhard Zumkeller, Jul 22 2002
STATUS
approved