The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A323415 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A323415

Numbers equal to the carryless sum of their divisors.
(history; published version)

#6 by Susanna Cuyler at Sun Jan 13 19:30:46 EST 2019

STATUS

proposed

approved

#5 by Rémy Sigrist at Sun Jan 13 16:24:15 EST 2019

STATUS

editing

proposed

#4 by Rémy Sigrist at Sun Jan 13 16:15:55 EST 2019

EXAMPLE

- the divisors of 14 are: 1, 3, 9, 27, 81,2, 7, 14,

#3 by Rémy Sigrist at Sun Jan 13 16:03:08 EST 2019

EXAMPLE

For k = 14:

- the divisors of 14 are: 1, 3, 9, 27, 81,

- 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.

#2 by Rémy Sigrist at Sun Jan 13 15:58:43 EST 2019

NAME

allocated for Rémy Sigrist

Numbers equal to the carryless sum of their divisors.

DATA

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

1,2

COMMENTS

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

LINKS

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

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

CROSSREFS

Cf. A323394.

KEYWORD

allocated

nonn,base

AUTHOR

Rémy Sigrist, Jan 13 2019

STATUS

approved

editing

#1 by Rémy Sigrist at Sun Jan 13 15:58:43 EST 2019

NAME

allocated for Rémy Sigrist

KEYWORD

allocated

STATUS

approved