List the nth prime quartet prefix
Prime numbers larger than 5 can end only in 1, 3, 7, or 9, but of course not all numbers ending in these four digits are prime. ...
4年以上 前
解決済み
Count the primes in Collatz sequences
Several Cody problems (21, 69, 42937, 44448, 44784, 52422) involve Collatz sequences. These start with a seed . If is odd, the ...
Determine whether a number is unprimeable
The number 204 is unprimeable because no single digit can be changed to make it prime. In contrast, the number 207 is not unprim...
List Honaker primes
The number 131 is the 32nd prime number. It is a Honaker prime because the sum of its digits (1+3+1) equals the sum of the digit...
5年弱 前
解決済み
Palindromic Prime
Palindromic Prime is a prime number that is also a palindromic number. (Wiki, OEIS)
If given a monotonic series (increment=1) ...
Determina si el número es primo
Primero, antes que nada: ¿Qué es un número primo?
Un número primo es cualquier número que solamente se puede dividir por 1 y ...
5年弱 前
解決済み
Sort Except Zeros
Sort the numbers in a vector. But the position of zeros should not be changed.
Example: sort_except_zeros( [5 3 0 0 2 4] ) == [...