A323414 - OEIS

%I #5 Jan 13 2019 19:30:36

%S 87,95,540,608,973,5940,7906,8787,9595,9715,54540,63796,64648,83337,

%T 599940,796677,836169,972223,5459940,6406408,6441128,6464648,7165526,

%U 8091755,9514464,54049140,54599940,64006408,64064648,64640648,82913331

%N Numbers whose carryless sum of divisors is zero.

%C Equivalently, numbers k such that A323394(k) = 0.

%H <a href="/index/Ca#CARRYLESS">Index entries for sequences related to carryless arithmetic</a>

%e For k = 87:

%e - the divisors of 87 are: 1, 3, 29, 87,

%e - the sum of units is: 1 + 3 + 9 + 7 = 20 == 0 (mod 10),

%e - the sum of tens is: 2 + 8 = 10 == 0 (mod 10),

%e - hence A323394(87) = 0 and 87 belongs to the sequence.

%o (PARI) isok(n, base=10) = my (v=[]); fordiv (n, d, my (w=Vecrev(digits(d, base))); v=vector(max(#v, #w), k, (if (k>#v, w[k], k>#w, v[k], (v[k]+w[k])%base)))); vecmax(v)==0

%Y Cf. A323394.

%K nonn,base

%O 1,1

%A _Rémy Sigrist_, Jan 13 2019