A053666 Product of digits of n-th prime.

2, 3, 5, 7, 1, 3, 7, 9, 6, 18, 3, 21, 4, 12, 28, 15, 45, 6, 42, 7, 21, 63, 24, 72, 63, 0, 0, 0, 0, 3, 14, 3, 21, 27, 36, 5, 35, 18, 42, 21, 63, 8, 9, 27, 63, 81, 2, 12, 28, 36, 18, 54, 8, 10, 70, 36, 108, 14, 98, 16, 48, 54, 0, 3, 9, 21, 9, 63, 84, 108, 45, 135, 126, 63, 189, 72, 216, 189

Offset

1,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Example

a(25) = 63 because the 25th prime is 97, and 9 * 7 = 63.
a(26) = 0 because the 26th prime is 101, and 1 * 0 * 1 = 0.

Maple

a:= n-> mul(i, i=convert(ithprime(n), base, 10)):
seq(a(n), n=1..78);  # Alois P. Heinz, Mar 11 2022

Mathematica

Table[Times@@IntegerDigits[Prime[n]], {n, 80}] (* Alonso del Arte, Feb 28 2014 *)

Prog

(PARI) a(n) = {d = digits(prime(n), 10); return (prod(i=1, #d, d[i])); } \\ Michel Marcus, Jun 12 2013
(Magma) [&*Intseq(NthPrime(n)): n in [1..80]]; // Vincenzo Librandi, Sep 15 2014
(Python)
from math import prod
from sympy import sieve
def pod(n): return prod(map(int, str(n)))
def a(n): return pod(sieve[n])
print([a(n) for n in range(1, 79)]) # Michael S. Branicky, Mar 11 2022

Crossrefs

Cf. A007954.

Sequence in context: A060418 A199975 A086355 * A101987 A178743 A126052

Adjacent sequences: A053663 A053664 A053665 * A053667 A053668 A053669

Keyword

nonn,base,easy

Author

Enoch Haga, Feb 16 2000

Status

approved