login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A052064
Cubes containing no palindromic substring except single digits.
6
0, 1, 8, 27, 64, 125, 216, 512, 729, 1728, 2197, 4096, 4913, 5832, 6859, 9261, 10648, 13824, 15625, 19683, 21952, 24389, 32768, 35937, 42875, 50653, 54872, 59319, 68921, 79507, 85184, 103823, 132651, 185193, 205379, 274625, 287496, 328509
OFFSET
1,3
COMMENTS
Sequence is probably finite.
Leading zeros in substring allowed so 52^2 = 140608 is rejected because 14{060}8 contains a palindromic substring.
LINKS
EXAMPLE
132651 (= 51^3) -> substrings 13, 32, 26, 65, 51, 132, 326, 265, 651, 1326, 3265, 2651, 13265, 32651 and 132651 are all non-palindromic.
MATHEMATICA
npsQ[n_]:=Count[Flatten[Table[Partition[IntegerDigits[n], i, 1], {i, 2, IntegerLength[ n]}], 1], _?(#==Reverse[#]&)]==0; Select[Range[ 0, 100]^3, npsQ] (* Harvey P. Dale, Dec 10 2016 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Patrick De Geest, Jan 15 2000
EXTENSIONS
Offset changed to 1 by Sean A. Irvine, Oct 17 2019
STATUS
approved