A293480 - OEIS

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A293480

Composite numbers k = concat(x,LSD(k)) such that the sum of the aliquot parts of k is equal to the sum of the aliquot parts of x.

0

1711, 22991, 109999, 112639, 130733, 269119, 318293, 390319, 1138399, 1319519, 1841839, 2010719, 2311919, 2581871, 6493519, 7355839, 7533599, 8332399

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Table of n, a(n) for n=1..18.

EXAMPLE

sum_aliquot_parts(22991) = 361 and sum_aliquot_parts(2299) = 361.

MAPLE

with(numtheory): P:=proc(q) local n, p, x; for n from 2 to q do

if not isprime(n) then x:=trunc(n/10); if sigma(n)-n=sigma(x)-x then print(n); fi; fi; od; end: P(10^6);

CROSSREFS

Cf. A010879 (LSD), A001065 (sum of aliquot parts)

Sequence in context: A241554 A352949 A129540 * A227218 A280113 A242102

Adjacent sequences: A293477 A293478 A293479 * A293481 A293482 A293483

KEYWORD

nonn,base,more

AUTHOR

Paolo P. Lava, Oct 10 2017

STATUS

approved