OFFSET
1,1
COMMENTS
Cooper and Kennedy (1997) noted that this sequence is infinite since 10^k is a term for all k>=1. They also noted that there can be no more than 2 consecutive numbers that are coprime to their digital sum since if 3|k then 3|A007953(k).
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
Curtis Cooper and Robert E. Kennedy, On the set of positive integers which are relatively prime to their digital sum and its complement, J. Inst. Math. & Comp. Sci. (Math. Ser.), Vol. 10 (1997), pp. 173-180.
MATHEMATICA
q[n_] := CoprimeQ[n, Plus @@ IntegerDigits[n]]; Select[Range[500], q[#] && q[# + 1] &]
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Amiram Eldar, Nov 22 2020
STATUS
approved