|
|
A124141
|
|
Numbers k such that there is a number m < k satisfying A000203(k) = A000203(m) = m + k - gcd(m,k).
|
|
1
|
|
|
38, 92, 153, 284, 332, 459, 494, 885, 956, 1035, 1358, 1784, 2295, 2528, 2678, 5434, 5607, 6027, 6255, 7564, 7928, 8235, 8648, 9729, 10325, 10413, 12008, 14104, 15813, 16198, 17794, 22712, 22936, 23247, 27082, 27626, 28917, 30938, 33082, 34688, 37790, 37816
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
LINKS
|
|
|
EXAMPLE
|
38 is in the sequence because A000203(24) = A000203(38) = 60 = 24 + 38 - gcd(24,38).
|
|
PROG
|
(PARI) isok(k) = {my(sk = sigma(k)); for (m=1, k, if ((sk == sigma(m)) && (sk == m + k - gcd(m, k)), return (1)); ); return (0); } \\ Michel Marcus, Oct 27 2019
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|