A371281 Last digit of the product of decimal digits of n.

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 2, 4, 6, 8, 0, 2, 4, 6, 8, 0, 3, 6, 9, 2, 5, 8, 1, 4, 7, 0, 4, 8, 2, 6, 0, 4, 8, 2, 6, 0, 5, 0, 5, 0, 5, 0, 5, 0, 5, 0, 6, 2, 8, 4, 0, 6, 2, 8, 4, 0, 7, 4, 1, 8, 5, 2, 9, 6, 3, 0, 8, 6, 4, 2, 0, 8, 6, 4, 2, 0, 9, 8

Offset

0,3

Comments

n=0 is taken as one 0 digit so that its product of digits is A007954(0) = 0.

Links

Alois P. Heinz, Table of n, a(n) for n = 0..10000

Formula

a(n) = A007954(n) mod 10.

a(n) = A010879(A007954(n)).

Example

n = 15: a(15) = 1*5 mod 10 = 5.
n = 26: a(26) = 2*6 mod 10 = 2.

Maple

a:= n-> `if`(n<10, n, irem(n, 10, 'q')*a(q) mod 10):
seq(a(n), n=0..92);  # Alois P. Heinz, Mar 17 2024

Mathematica

a[n_] := Mod[Times @@ IntegerDigits[n], 10]; Array[a, 100, 0] (* Amiram Eldar, Mar 17 2024 *)

Prog

(Python)
from math import prod
def a(n): return prod(map(int, str(n)))%10
print([a(n) for n in range(93)]) # Michael S. Branicky, Mar 17 2024
(PARI) a(n) = if (n==0, 0, vecprod(digits(n)) % 10); \\ Michel Marcus, Mar 17 2024

Crossrefs

Cf. A007954, A010879, A036987 (similar for 2 instead of 10), A053837.

Sequence in context: A175421 A175420 A062078 * A031347 A087471 A128212

Adjacent sequences: A371278 A371279 A371280 * A371282 A371283 A371284

Keyword

nonn,base

Author

Ctibor O. Zizka, Mar 17 2024

Status

approved