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 A087316 a(n) = Sum_{k=1..n} prime(k)^prime(n-k+1). 10
 4, 17, 84, 545, 7824, 281771, 51540600, 3347558057, 1146374959980, 288113965730819, 529172633067826888, 283453407513524913023, 4122282265785671687518812, 1586581830624893452605127040309 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS T. D. Noe, Table of n, a(n) for n=1..50 EXAMPLE Examples from Jonathan Vos Post, Jan 06 2006: a(1) = 4 because prime(1)^prime(1) = 2^2 = 4. a(2) = 17 because prime(1)^prime(2) + prime(2)^prime(1) = 2^3 + 3^2 = 17. a(3) = 84 because 2^5 + 3^3 + 5^2 = 84. a(4) = 545 = 2^7 + 3^5 + 5^3 + 7^2. a(5) = 7824 = 2^11 + 3^7 + 5^5 + 7^3 + 11^2. a(6) = 281771 = 2^13 + 3^11 + 5^7 + 7^5 + 11^3 + 13^2. a(7) = 51540600 = 2^17 + 3^13 + 5^11 + 7^7 + 11^5 + 13^3 + 17^2. a(8) = 3347558057 = 2^19 + 3^17 + 5^13 + 7^11 + 11^7 + 13^5 + 17^3 + 19^2. a(9) = 1146374959980 = 2^23 + 3^19 + 5^17 + 7^13 + 11^11 + 13^7 + 17^5 + 19^3 + 23^2. MAPLE a:=n->sum(ithprime(k)^ithprime(n-k+1), k=1..n): seq(a(n), n=1..16); # Emeric Deutsch, Apr 13 2005 PROG (PARI) a(n) = sum(k=1, n, prime(k)^prime(n-k+1)); \\ Michel Marcus, Aug 20 2019 CROSSREFS Cf. A000040, A005408, A087315, A113122, A113153, A113154. Sequence in context: A200716 A093904 A093344 * A104979 A081052 A020074 Adjacent sequences:  A087313 A087314 A087315 * A087317 A087318 A087319 KEYWORD nonn AUTHOR Amarnath Murthy, Sep 03 2003 EXTENSIONS More terms from Sam Alexander, Oct 20 2003 Further terms from Emeric Deutsch, Apr 13 2005 Edited by N. J. A. Sloane, Aug 19 2008 at the suggestion of R. J. Mathar STATUS approved

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Last modified October 14 01:36 EDT 2019. Contains 327994 sequences. (Running on oeis4.)