A065379 Palindromic squares with a prime root.

4, 9, 121, 10201, 94249, 900075181570009, 10022212521222001, 12124434743442121, 12323244744232321, 12341234943214321, 1022321210249420121232201, 1210024420147410244200121, 1210222232227222322220121, 1212223242528252423222121, 10022032324432823442323022001

Offset

1,1

Comments

Record sporadic palindromic square with a prime root is 186627875420278656872024578726681.

Links

Table of n, a(n) for n=1..15.

Patrick De Geest, Palindromic Squares in bases 2 to 17

G. L. Honaker, Jr. and C. Caldwell, Prime Curios!

William Rex Marshall, Palindromic Squares [Internet Archive Wayback Machine]

Formula

a(n) = A065378(n)^2. - Pontus von Brömssen, Feb 03 2026

Example

a(6) = 900075181570009 = p^2 with p = 30001253, a prime.

Crossrefs

Cf. A065378, A002778, A002779, A034822, A028816, A016106, A059744, A016113, A007573.

Sequence in context: A057136 A048411 A225739 * A063783 A378745 A168138

Adjacent sequences: A065376 A065377 A065378 * A065380 A065381 A065382

Keyword

nonn,base

Author

Patrick De Geest, Nov 03 2001

Extensions

a(7) inserted and a(14)-a(15) (using A065378) from Pontus von Brömssen, Feb 03 2026

Status

approved