A323414 Numbers whose carryless sum of divisors is zero.

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

Author

Rémy Sigrist, Jan 13 2019

Keywords

• nonn
• base

Comments

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

Examples

			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.
		

Links

• Index entries for sequences related to carryless arithmetic

Crossrefs

Cf. A323394.

Programs

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