Search a number
idoneal numbers
A number which cannot be written as a⋅b + b⋅c + c⋅a, for 0<a<b<c. more

The known idoneal numbers are :
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 13, 15, 16, 18, 21, 22, 24, 25, 28, 30, 33, 37, 40, 42, 45, 48, 57, 58, 60, 70, 72, 78, 85, 88, 93, 102, 105, 112, 120, 130, 133, 165, 168, 177, 190, 210, 232, 240, 253, 273, 280, 312, 330, 345, 357, 385, 408, 462, 520, 760, 840, 1320, 1365, 1848.

Distribution of the remainders when the numbers in this family are divided by n=2, 3,..., 11. (I took into account 65 values, from 1 to 1848).

n\r 0  1 
24025 2 
337253 3 
42422163 4 
526415173 5 
6229215161 6 
718121341143 7 
820108141282 8 
947117911691 9 
1016210721025101 10 
111011578643353

A pictorial representation of the table above
motab
Imagine to divide the members of this family by a number n and compute the remainders. Should they be uniformly distributed, each remainder from 0 to n-1 would be obtained in about (1/n)-th of the cases. This outcome is represented by a white square. Reddish (resp. bluish) squares represent remainders which appear more (resp. less) frequently than 1/n.