|
|
A352440
|
|
Numbers k whose decimal expansion starts with the sum of the last three digits of k.
|
|
1
|
|
|
100, 109, 119, 129, 139, 149, 159, 169, 179, 189, 199, 200, 300, 400, 500, 600, 700, 800, 900, 1001, 1010, 1019, 1028, 1037, 1046, 1055, 1064, 1073, 1082, 1091, 1100, 1119, 1128, 1137, 1146, 1155, 1164, 1173, 1182, 1191, 1219, 1228, 1237, 1246, 1255, 1264, 1273, 1282, 1291, 1319, 1328, 1337, 1346
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
LINKS
|
|
|
EXAMPLE
|
100 is a term because "100" starts with "1" = 1 + 0 + 0;
109 is a term because "109" starts with "10" = 1 + 0 + 9;
1346 is a term because "1346" starts with "13" = 3 + 4 + 6; etc.
|
|
MATHEMATICA
|
q[n_] := Module[{d = IntegerDigits[n], s, ds, nds}, s = Plus @@ d[[-3 ;; -1]]; ds = IntegerDigits[s]; nds = Length[ds]; ds == d[[1 ;; nds]]]; Select[Range[100, 1400], q] (* Amiram Eldar, Mar 16 2022 *)
|
|
PROG
|
(Python)
def ok(n):
s = str(n)
return n > 99 and s.startswith(str(sum(map(int, s[-3:]))))
|
|
CROSSREFS
|
|
|
KEYWORD
|
base,nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|