|
|
A063981
|
|
Numbers n such that t(n) = sigma(n) - n, where t(n) = A008472(n+1) - A008472(n).
|
|
0
|
|
|
2, 4, 9, 16, 81, 85, 256, 931, 65536, 4599097, 6309263, 16905401, 43046721, 54116239, 68229263, 98643563, 208288271, 222933913, 226461649, 230893123, 280399957, 381001633, 412016873, 417814973, 485674237, 620336281, 736284077
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
LINKS
|
|
|
MATHEMATICA
|
a = 0; b = 0; Do[a = b; b = Apply[ Plus, Transpose[ FactorInteger[n + 1]] [[1]]]; If[ b - a == DivisorSigma[1, n] - n, Print[n]], {n, 1, 2*10^7} ]
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|