|
|
A218248
|
|
Recurring digital invariants of order 7.
|
|
3
|
|
|
80441, 86874, 253074, 376762, 922428, 982108, 1152428, 2191663, 2755907, 2767918, 8139850
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
LINKS
|
|
|
EXAMPLE
|
2755907: 2^7 + 7^7 + 5^7 + 5^7 + 9^7 + 0^7 + 7^7 = 6586433
6586433: 6^7 + 5^7 + 8^7 + 6^7 + 4^7 + 3^7 + 3^7 = 2755907,
so 2755907 is an order 7 recurring digital invariant.
|
|
MATHEMATICA
|
lst = {}; f[n_] := Total[IntegerDigits[n]^7]; Do[a = n; Do[a = f[a]; If[a < n, Break[]]; If[a == n && ! n == f[n], AppendTo[lst, n]; Break[]], {92}], {n, 10^7}]; lst
|
|
CROSSREFS
|
|
|
KEYWORD
|
base,fini,full,nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|