1,1

T. D. Noe, Table of n, a(n) for n=1..50

Examples from Jonathan Vos Post (jvospost2(AT)yahoo.com), 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.

a:=n->sum(ithprime(k)^ithprime(n-k+1), k=1..n): seq(a(n), n=1..16); (Deutsch)

Cf. A000040, A005408, A087315, A113122, A113153, A113154.

Adjacent sequences: A087313 A087314 A087315 this_sequence A087317 A087318 A087319

nonn,new

Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Sep 03 2003

More terms from Sam Alexander (amnalexander(AT)yahoo.com), Oct 20 2003

Further terms from Emeric Deutsch (deutsch(AT)duke.poly.edu), Apr 13 2005

Edited by njas, Aug 19 2008 at the suggestion of R. J. Mathar