A046403 Numbers with exactly 5 distinct prime factors each of which is a palindrome.

2310, 21210, 27510, 31710, 33330, 38010, 40110, 43230, 46662, 49830, 59730, 60522, 63030, 65730, 69762, 74130, 77770, 78330, 80430, 83622, 88242, 100870, 103290, 116270, 116490, 116655, 123090, 126390, 139370, 144606, 147070, 151305, 152670, 158970, 163086, 165270, 167370

Offset

1,1

Links

David A. Corneth, Table of n, a(n) for n = 1..10000

Example

144606 = 2 * 3 * 7 * 11 * 313 is in the sequence as it has exactly 5 prime factors each of which is a palindrome. - David A. Corneth, Aug 30 2020

Mathematica

ppf5Q[n_]:=With[{f=Select[FactorInteger[n], #[[2]]==1&][[;; , 1]]}, Length[f]==5&&AllTrue[f, PalindromeQ]]; Select[Range[200000], ppf5Q] (* Harvey P. Dale, Dec 26 2025 *)

Crossrefs

Cf. A002385, A014614, A046400, A046401, A046402, A046403, A046371.

Sequence in context: A264718 A147572 A046303 * A288072 A087978 A384507

Adjacent sequences: A046400 A046401 A046402 * A046404 A046405 A046406

Keyword

nonn,easy,base

Author

Patrick De Geest, Jun 15 1998

Extensions

Offset changed to 1 and more terms from David A. Corneth, Aug 30 2020

Definition clarified by Harvey P. Dale, Dec 26 2025

Status

approved