OFFSET
1,1
COMMENTS
This sequence is mentioned in A077320. - Omar E. Pol, Mar 12 2012
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..10000
FORMULA
a(n) ~ 0.5 n^3 log n. - Charles R Greathouse IV, Nov 22 2011
EXAMPLE
The 4th prime is 7, the 4th triangular number is 10, therefore a(4) = 7*10 = 70.
MATHEMATICA
With[{nn=60}, Prime[Range[nn]]Accumulate[Range[nn]]]
PROG
(PARI) a(n)=prime(n)*binomial(n+1, 2) \\ Charles R Greathouse IV, Nov 22 2011
(Python)
from sympy import prime
def a(n): return prime(n) * n*(n+1)//2
print([a(n) for n in range(1, 41)]) # Michael S. Branicky, Sep 01 2022
CROSSREFS
KEYWORD
nonn
AUTHOR
Harvey P. Dale, Oct 15 2011
STATUS
approved