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A143682
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a(n) = (prime(n)^4 - prime(n^4))/2, where prime(n) is the n-th prime.
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2
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7, 14, 103, 391, 5002, 8967, 31065, 45724, 107077, 301276, 382000, 820141, 1246909, 1479730, 2129740, 3534420, 5523879, 6237871, 9209731, 11625564, 12865129, 17844972, 21754756, 28999632, 41437737, 48684207, 52341667, 60941856
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OFFSET
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1,1
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LINKS
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EXAMPLE
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a(1) = (prime(1)^2^2 - prime(1^2^2))/2 = (16 - 2)/2 = 14/2 = 7,
a(2) = (prime(2)^2^2 - prime(2^2^2))/2 = (81 - 53)/2 = 28/2 = 14,
a(3) = (prime(3)^2^2 - prime(3^2^2))/2 = (625 - 419)/2 = 206/2 = 103,
a(4) = (prime(4)^2^2 - prime(4^2^2))/2 = (2401 - 1619)/2 = 782/2 = 391 = a(4),
a(5) = (prime(5)^2^2 - prime(5^2^2))/2 = (14641 - 4637)/2 = 10004/2 = 5002,
etc.
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MAPLE
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A143682 := proc(n) (ithprime(n)^4-ithprime(n^4))/2 ; end: for n from 1 to 50 do printf("%d, ", A143682(n)) ; od: # R. J. Mathar, Nov 05 2008
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MATHEMATICA
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Table[(Prime[n]^4 - Prime[n^4])/2, {n, 40}] (* G. C. Greubel, May 29 2021 *)
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PROG
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(PARI) a(n) = (prime(n)^4 - prime(n^4))/2; \\ Michel Marcus, Oct 05 2015
(Magma) [(NthPrime(n)^4 - NthPrime(n^4))/2: n in [1..30]]; // Vincenzo Librandi, Oct 05 2015
(Sage) [(nth_prime(n)^4 - nth_prime(n^4))/2 for n in (1..40)] # G. C. Greubel, May 29 2021
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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