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A284667 Numbers of form p^i + p^j for at least two values of p prime and i, j > 0. 0
6, 10, 12, 18, 30, 34, 36, 130, 132, 514, 131074 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
2*F is in the sequence, where F is a Fermat prime.
a(12) (if it exists) > 2*10^9. - Giovanni Resta, Apr 02 2017
LINKS
Table of n, a(n) for n=1..11.
EXAMPLE
10 = 2^3 + 2^1 = 5^1 + 5^1.
30 = 3^3 + 3^1 = 5^2 + 5^1.
132 = 2^7 + 2^2 = 11^2 + 11^1.
PROG
(PARI) limit=L; v=vector(limit); for(n=1, limit, forprime(p=2, n/2, for(k=1, logint(n\2, 2), for(j=k, logint(n, 2), forprime(q=p+1, n/2, for(t=1, logint(n\2, 3), for(u=t, logint(n, 3), if(n-p^k==p^j&&n-q^t==q^u, v[n]=1)))))))); for(n=1, limit, if(v[n], print1(n", ")))
CROSSREFS
Cf. A019434, A246655, A284665.
Sequence in context: A076763 A064712 A348629 * A315132 A352101 A315133
Adjacent sequences: A284664 A284665 A284666 * A284668 A284669 A284670
KEYWORD
nonn,more
AUTHOR
Gionata Neri, Mar 31 2017
STATUS
approved

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Last modified August 18 15:26 EDT 2024. Contains 375269 sequences. (Running on oeis4.)