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 A122703 Primes of the form p^2 + q^7 where p and q are primes. 1
 137, 823547, 271818611111, 9974730326005061, 630634881591804953, 32525450580470426321, 2169562730596120989977, 3863897579789788264121, 122288345645958900577487, 680203568668250740574183, 3167337505302652506404471, 6421072852468062867774503, 8417887306491957134503937, 21307550075749197394472141 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS p and q cannot both be odd. Thus p=2 or q=2. After 3^2 + 2^7 = 137, all solutions are of the form 2^2 + q^7. LINKS Robert Israel, Table of n, a(n) for n = 1..5449 FORMULA {a(n)} = {p^2 + q^7 in A000040 where p and q are in A000040}. EXAMPLE a(1) = 3^2 + 2^7 = 137. a(2) = 2^2 + 7^7 = 823547. a(3) = 2^2 + 43^7 = 271818611111. a(4) = 2^2 + 193^7 = 9974730326005061. a(5) = 2^2 + 349^7 = 630634881591804953. MAPLE N:= 10^30: # to get all terms <= N A:= select(isprime, {137, seq(2^2 + q^7, q = select(isprime, [2, seq(i, i=3..floor((N-4)^(1/7)), 2)]))}): sort(convert(A, list)); # Robert Israel, Jan 24 2018 CROSSREFS Cf. A000040, A045700 (Primes of form p^2+q^3 where p and q are primes). Sequence in context: A134874 A064104 A300407 * A200335 A351237 A292094 Adjacent sequences:  A122700 A122701 A122702 * A122704 A122705 A122706 KEYWORD nonn AUTHOR Jonathan Vos Post, Sep 22 2006 EXTENSIONS More terms from Robert Israel, Jan 24 2018 STATUS approved

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Last modified May 27 12:58 EDT 2022. Contains 354097 sequences. (Running on oeis4.)