1,1

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

Examples from Jonathan Vos Post (jvospost3(AT)gmail.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.

Sequence in context: A052315 A093904 A093344 this_sequence A104979 A081052 A020074

Adjacent sequences: A087313 A087314 A087315 this_sequence A087317 A087318 A087319

nonn

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 N. J. A. Sloane (njas(AT)research.att.com), Aug 19 2008 at the suggestion of R. J. Mathar