A071276 a(1) = 1; a(n) = smallest palindrome which is a nontrivial product of n distinct palindromes.

1, 6, 66, 252, 2112, 46464, 23677632, 880121088, 88892229888, 2992770772992, 65432159295123456, 466336152251633664

Offset

1,2

Comments

From Giovanni Resta, Oct 08 2025: (Start)

a(10) = 2992770772992 = 949 * 808 * 44 * 11 * 8 * 7 * 6 * 4 * 3 * 2.

a(11) = 65432159295123456 = 70607 * 272 * 121 * 101 * 22 * 11 * 8 * 6 * 4 * 3 * 2.

a(12) = 466336152251633664 = 10901 * 737 * 676 * 44 * 22 * 11 * 8 * 7 * 6 * 4 * 3 * 2.

(End)

Links

Table of n, a(n) for n=1..12.

Example

252=2*3*6*7 => a(4)=252.

Crossrefs

Cf. A071277, A378140.

Sequence in context: A048537 A133424 A045641 * A119172 A064167 A175455

Adjacent sequences: A071273 A071274 A071275 * A071277 A071278 A071279

Keyword

base,nonn,more

Author

Amarnath Murthy, Jun 07 2002

Extensions

Corrected and extended by Sascha Kurz, Jan 02 2003

a(7)-a(8) from Sean A. Irvine, Jul 07 2024

a(9) from Michael S. Branicky, Jul 08 2024

Name corrected by Robert Israel, Jan 08 2025

a(10)-a(12) from Giovanni Resta, Oct 08 2025

Status

approved