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A323414
Numbers whose carryless sum of divisors is zero.
1
87, 95, 540, 608, 973, 5940, 7906, 8787, 9595, 9715, 54540, 63796, 64648, 83337, 599940, 796677, 836169, 972223, 5459940, 6406408, 6441128, 6464648, 7165526, 8091755, 9514464, 54049140, 54599940, 64006408, 64064648, 64640648, 82913331
OFFSET
1,1
COMMENTS
Equivalently, numbers k such that A323394(k) = 0.
EXAMPLE
For k = 87:
- the divisors of 87 are: 1, 3, 29, 87,
- the sum of units is: 1 + 3 + 9 + 7 = 20 == 0 (mod 10),
- the sum of tens is: 2 + 8 = 10 == 0 (mod 10),
- hence A323394(87) = 0 and 87 belongs to the sequence.
PROG
(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
CROSSREFS
Cf. A323394.
Sequence in context: A295698 A095597 A095583 * A231403 A256083 A038005
KEYWORD
nonn,base
AUTHOR
Rémy Sigrist, Jan 13 2019
STATUS
approved