OFFSET
1,1
COMMENTS
Only two numbers have more than one solution, 294, which has two:
294 = 43 + 251,
294 = 53 + 241.
And 564, which has three:
564 = 23 + 541,
564 = 41 + 523,
564 = 43 + 521.
Also, permutations of numbers are extremely common. 69 and 96; 249,294 and 429; 546 and 564; 1428 and 2148; 1455, 1545, 4155, 4515 and 5415; 2346 and 4236; 3543 and 5433. In fact, there are only 3 numbers from a total of 21 that do not have any permutations associated with it. These are 51, 438 and 474.
Another odd fact: the sum of the digits of every single value, except 51, is 15. (note: not actually odd. Since 1 + 2 + 3 + 4 + 5 = 15 and digitSum (a + b) = digitSum( digitSum(a) + digitSum(b) ))
EXAMPLE
51 = 2 + 3 + 5 + 41.
69 = 5 + 23 + 41.
96 = 2 + 41 + 53.
CROSSREFS
KEYWORD
nonn,base,fini,full
AUTHOR
Raffa Freitas, Aug 12 2014
STATUS
approved