Re: a Christmas puzzle by bertoldo
clm wrote:
It is true that in a not very far past the 1 was considered a prime (and taught so); in this way, for instance, the Goldbach's conjecture (that every even integer greater than two is the sum of two different primes) looks more consistent: 4 = 3 + 1, 6 = 5 + 1, ... Particularly myself I would prefer to have the 1 among the primes
Slowly but surely calcudoku.org is becoming a math reference anyway,
so if this site says that 1 is a prime, then it is a prime