OFFSET
1,4
LINKS
FORMULA
EXAMPLE
36 has in total 9 = A001055(36) factorizations:
factors in decimal in primorial base Do they generate carries when summed?
[3, 3, 2, 2] [11, 11, 10, 10] Yes, as A049345(3+3+2+2) = "120".
[4, 3, 3] [20, 11, 11] Yes, in the least significant place.
[6, 3, 2] [100, 11, 10] No, 6+3+2 = 11 = "121".
[6, 6] [100, 100] No, 6+6 = 12 = "200".
[9, 2, 2] [111, 10, 10] Yes, in the second place from right.
[9, 4] [111, 20] Ditto.
[12, 3] [200, 11] No, 12+3 = 15 = "211".
[18, 2] [300, 10] No, 18+2 = 20 = "310".
[36] [1100] No, as a single factor never does.
Thus only five of the sums are carryfree, and a(36) = 5.
PROG
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Antti Karttunen, Nov 29 2022
STATUS
approved