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A332659
Alternate multiplying and adding prime numbers: a(2n) = a(2n-1) + prime(2n+1) and a(2n-1) = a(2n) * prime(2n-2) for n >= 1.
3
6, 11, 77, 88, 1144, 1161, 22059, 22082, 640378, 640409, 23695133, 23695174, 1018892482, 1018892529, 54001304037, 54001304096, 3294079549856, 3294079549923, 233879648044533, 233879648044606, 18476492195523874, 18476492195523957, 1644407805401632173
OFFSET
1,1
EXAMPLE
a(1) = 2 * 3 = 6;
a(2) = 6 + 5 = 11;
a(3) = 11 * 7 = 77.
PROG
(Python)
from sympy import primerange
p = list(primerange(1, 1000))
def a(n):
out = p[0] * p[1]
for i in range(1, n):
if i % 2:
out += p[i + 1]
else:
out *= p[i + 1]
return out
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Adnan Baysal, Feb 18 2020
STATUS
approved