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Search: id:A134657
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| A134657 |
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Numbers of the form p^2 + q^3 + r^4 with p, q and r primes. |
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+0
1
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| 28, 33, 47, 49, 52, 68, 73, 92, 93, 98, 112, 114, 117, 133, 138, 145, 150, 157, 164, 166, 190, 193, 210, 212, 215, 229, 231, 255, 258, 262, 277, 310, 313, 327, 332, 363, 368, 375, 378, 384, 385, 397, 404, 408, 428, 430, 433, 449, 450, 469, 473, 480, 495
(list; graph; listen)
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OFFSET
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1,1
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LINKS
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Project Euler, Problem 87.
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EXAMPLE
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a(1) = 28 = 2^2 + 2^3 + 2^4 is the smallest sum of a prime square, cube and 4th power.
a(2) = 33 = 3^2 + 2^3 + 2^4 is the next number of that form.
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PROGRAM
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(PARI) is_p87(n, t, tt)={forprime(p=2, sqrtn(n, 4), t=n-p^4; forprime(q=2, sqrtn(t, 3), issquare(t-q^3, &tt)|next; isprime(tt)&return(1)))} print_p87(Nmax=999)=for(n=1, Nmax, is_p87(n)&print1(n", "))
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CROSSREFS
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Cf. A045701.
Sequence in context: A031171 A121018 A090637 this_sequence A138687 A055576 A101421
Adjacent sequences: A134654 A134655 A134656 this_sequence A134658 A134659 A134660
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KEYWORD
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easy,nonn
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AUTHOR
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M. F. Hasler (Maximilian.Hasler(AT)gmail.com), Jan 25 2008
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