A112875 Product of digits of n-th base 10 palindrome.

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 4, 9, 16, 25, 36, 49, 64, 81, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 0, 9, 18, 27, 36, 45, 54, 63, 72, 81, 0, 16, 32, 48, 64, 80, 96, 112, 128, 144, 0, 25, 50, 75, 100, 125, 150, 175, 200, 225, 0, 36, 72, 108, 144, 180, 216

Offset

1,3

Links

Table of n, a(n) for n=1..76.

Formula

a(n) = A007954(A002113(n)). - Michel Marcus, Jun 14 2024~

Prog

(Python)
from math import prod
def A112875(n):
    if n == 1: return 0
    y = 10*(x:=10**(len(str(n>>1))-1))
    return int((s:=str(n-x))[-1])*prod(int(d) for d in s[:-1])**2 if n<x+y else prod(map(int, str(n-y)))**2 # Chai Wah Wu, Jun 14 2024

Crossrefs

Cf. A002113, A007954.

Sequence in context: A264600 A138470 A325454 * A113018 A113009 A068064

Adjacent sequences: A112872 A112873 A112874 * A112876 A112877 A112878

Keyword

base,easy,nonn

Author

Giovanni Teofilatto, Jan 02 2006

Extensions

More terms from Joshua Zucker, May 03 2006

Status

approved