OFFSET
1,1
COMMENTS
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
FORMULA
EXAMPLE
a(1) = Sum_{i=1..1} prime(i)*(3*prime(i)-1)/2 = P(2) = 5.
a(2) = Sum_{i=1..2} prime(i)*(3*prime(i)-1)/2 = P(2) + P(3) = 17.
a(3) = Sum_{i=1..11} prime(i)*(3*prime(i)-1)/2 = P(2) + P(3) + P(5) + P(7) + P(11) + P(13) + P(17) + P(19) + P(23) + P(29) + P(31) = 4957.
a(4) = P(2) + ... + P(103) = 129277.
MAPLE
P:=n->n*(3*n-1)/2: seq(P(n), n=0..10): a:=proc(n) if isprime(sum(P(ithprime(j)), j=1..n))=true then sum(P(ithprime(j)), j=1..n) else fi end: seq(a(n), n=1..600); # Emeric Deutsch, Apr 15 2006
MATHEMATICA
Module[{nn=4000, pn, pr}, pn=PolygonalNumber[5, Range[nn]]; pr=Table[If[ PrimeQ[ n], 1, 0], {n, nn}]; Select[Accumulate[Pick[pn, pr, 1]], PrimeQ]] (* Harvey P. Dale, Jan 27 2020 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Jonathan Vos Post, Apr 03 2006
EXTENSIONS
More terms from Emeric Deutsch, Apr 15 2006
STATUS
approved