A332659 - OEIS

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.

6, 11, 77, 88, 1144, 1161, 22059, 22082, 640378, 640409, 23695133, 23695174, 1018892482, 1018892529, 54001304037, 54001304096, 3294079549856, 3294079549923, 233879648044533, 233879648044606, 18476492195523874, 18476492195523957, 1644407805401632173

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OFFSET

1,1

LINKS

Table of n, a(n) for n=1..23.

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

Cf. A047904, A047905, A077138, A222559, A332657, A332660.

Sequence in context: A077705 A077697 A283820 * A219702 A013321 A192893

Adjacent sequences: A332656 A332657 A332658 * A332660 A332661 A332662

KEYWORD

nonn,easy

AUTHOR

Adnan Baysal, Feb 18 2020

STATUS

approved