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.
Original entry on oeis.org
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
a(1) = 2 * 3 = 6;
a(2) = 6 + 5 = 11;
a(3) = 11 * 7 = 77.
A332660
Alternate adding and multiplying Fibonacci numbers: a(0) = F(0) + F(1), for n >= 0, a(2n+1) = a(2n) * F(2n+2), a(2n+2) = a(2n+1) + F(2n+3).
Original entry on oeis.org
1, 1, 3, 9, 14, 112, 125, 2625, 2659, 146245, 146334, 21072096, 21072329, 7944268033, 7944268643, 7840993150641, 7840993152238, 20261126305382992, 20261126305387173, 137066519455944225345
Offset: 0
a(0) = 0 + 1 = 1;
a(1) = 1 * 1 = 1;
a(2) = 1 + 2 = 3;
a(3) = 3 * 3 = 9;
a(4) = 9 + 5 = 14.
-
a[0] = 1; a[n_] := a[n] = If[OddQ[n], a[n-1] * Fibonacci[n+1], a[n-1] + Fibonacci[n+1]]; Array[a, 20, 0] (* Amiram Eldar, Mar 28 2020 *)
-
from sympy import fibonacci
f = [fibonacci(n) for n in range(100)]
def a(n):
out = f[0] + f[1]
for i in range(1, n):
if i%2:
out *= f[i+1]
else:
out += f[i+1]
return out
A333591
Alternate multiplying and adding Fibonacci numbers: a(0) = F(0) * F(1), for n >= 0, a(2n+1) = a(2n) + F(2n+2), a(2n+2) = a(2n+1) * F(2n+3).
Original entry on oeis.org
0, 1, 2, 5, 25, 33, 429, 450, 15300, 15355, 1366595, 1366739, 318450187, 318450564, 194254844040, 194254845027, 310224987508119, 310224987510703, 1297050672782249243, 1297050672782256008, 14197516664274574263568, 14197516664274574281279
Offset: 0
a(0) = 0 * 1 = 0;
a(1) = 0 + 1 = 1;
a(2) = 1 * 2 = 2;
a(3) = 2 + 3 = 5;
a(4) = 5 * 5 = 25.
-
a[0] = 0; a[n_] := a[n] = If[EvenQ[n], a[n-1] * Fibonacci[n+1], a[n-1] + Fibonacci[n+1]]; Array[a, 22, 0] (* Amiram Eldar, Mar 28 2020 *)
-
from sympy import fibonacci
f = [fibonacci(n) for n in range(200)]
def a(n):
out = f[0] * f[1]
for i in range(1, n+1):
if i%2:
out += f[i+1]
else:
out *= f[i+1]
return out
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