cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A053666 Product of digits of n-th prime.

Original entry on oeis.org

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

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Author

Enoch Haga, Feb 16 2000

Keywords

Examples

			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.
		

Crossrefs

Cf. A007954.

Programs

  • Magma
    [&*Intseq(NthPrime(n)): n in [1..80]]; // Vincenzo Librandi, Sep 15 2014
    
  • 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 *)
  • PARI
    a(n) = {d = digits(prime(n), 10); return (prod(i=1, #d, d[i]));} \\ Michel Marcus, Jun 12 2013
    
  • 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