(In reply to
computer solution by Charlie)
Sloane shows 42042 for k=11, rather than my 7871, so something went wrong. Apparently UBASIC returns a zero for the prmdiv function if its largest prime divisor is bigger than a certain value, such as in:
?prmdiv(98765432137)
0
C'est l'informatique.

Posted by Charlie
on 20120108 13:29:35 