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A358271
Product of the digits of 3^n.
0
1, 3, 9, 14, 8, 24, 126, 112, 180, 1296, 0, 1372, 240, 3240, 217728, 0, 0, 0, 0, 24192, 0, 0, 0, 2709504, 6635520, 0, 66355200, 8534937600, 731566080, 0, 0, 10369949184, 0, 0, 399983754240, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 6243870843076608000
OFFSET
0,2
COMMENTS
a(68) is likely the last nonzero term; see A030700 and A238939. - Michael S. Branicky, Nov 06 2022
FORMULA
a(n) = A007954(A000244(n)).
EXAMPLE
For a(0), 3^0 = 1 with product of digits 1;
for a(3), 3^3 = 27 with product of digits 2*7 = 14;
for a(10), 3^10 = 59049 with product of digits 5*9*0*4*9 = 0.
MATHEMATICA
a[n_] := Times @@ IntegerDigits[3^n]; Array[a, 69, 0] (* Amiram Eldar, Nov 07 2022 *)
PROG
(Python)
from math import prod
def a(n): return prod(map(int, str(3**n)))
print([a(n) for n in range(69)]) # Michael S. Branicky, Nov 06 2022
(PARI) a(n) = vecprod(digits(3^n)); \\ Michel Marcus, Nov 07 2022
CROSSREFS
Cf. A014257.
Sequence in context: A134190 A047905 A134904 * A310324 A092476 A291641
KEYWORD
nonn,base
AUTHOR
Joseph Caliendo, Nov 06 2022
EXTENSIONS
More terms from Michael S. Branicky, Nov 06 2022
STATUS
approved