A323394 -id:A323394 - cp's OEIS frontend

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

Rémy Sigrist, Jan 13 2019

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

			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.

Index entries for sequences related to carryless arithmetic

Cf. A323394.

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

A323415 Numbers equal to the carryless sum of their divisors.

Original entry on oeis.org

1, 14, 84, 120, 1180, 1450, 10180, 12784, 100180, 101180, 114500, 139204, 1100180, 10000180, 10010180, 10111180, 11000180, 85937220, 101011180, 101101180, 101110180, 101111180, 110000180, 111001180, 111100180, 111101180, 111110180

Offset: 1

Rémy Sigrist, Jan 13 2019

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

			For k = 14:
- the divisors of 14 are: 1, 2, 7, 14,
- the sum of the units are: 1 + 2 + 7 + 4 = 14 == 4 (mod 10),
- the sum of the tens are: 1,
- hence A323394(14) = 14 and 14 belongs to the sequence.

Index entries for sequences related to carryless arithmetic

Cf. A323394.

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)))); fromdigits(Vecrev(v), base)==n

cp's OEIS Frontend

A323414 Numbers whose carryless sum of divisors is zero.

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