123454321
domain: N
Appears in sequences
- Wonderful Demlo numbers: a(n) = ((10^n - 1)/9)^2.at n=4A002477
- Palindromic squares.at n=24A002779
- Concatenation of sequence (1, 2, ..., floor((n-1)/2), floor(n/2), floor(n/2)-1, ..., 1) for n >= 1.at n=8A007907
- Palindromic squares with an odd number of digits.at n=22A028817
- Squares whose consecutive digits differ by 1.at n=8A048411
- Palindromes whose square root is a palindrome.at n=18A057136
- Odd number of digits palindrome based on sequential digits.at n=4A057139
- Squares whose consecutive digits vary by at most 1.at n=18A061850
- Smallest square beginning with concatenation of first n natural numbers.at n=4A068117
- Palindromic perfect powers.at n=28A075786
- Catalan paths: numbers starting with 1 and ending with 1 where each digit is positive and adjacent digits differ by 1.at n=22A079215
- Wonderful Demlo numbers A002477 whose digit sums are squares.at n=4A080162
- Repunit powers.at n=18A083278
- Squares in which the neighboring digits differ at most by 1. Neighbors of 1 are 0 and 2, neighbors of 0 are 1 and 9.at n=21A087553
- Giza numbers.at n=30A134810
- a(n) is obtained by starting with 1, sequentially concatenating all decimal numbers up to n, and then, starting from n-1, sequentially concatenating all decimal numbers down to 1.at n=4A173426
- Squares of A057148 taken as decimal numbers.at n=10A176923
- Giza nonprimes.at n=24A182775
- Concatenation of the palindromic numbers (A002113) in increasing order up to the n-th term and then in decreasing order.at n=4A261570
- Powers of 11111.at n=2A291946