212212
domain: N
Appears in sequences
- n written in fractional base 3/2.at n=35A024629
- Decimal expansion of a(n) is given by the first n terms of the periodic sequence with initial period 2,1,2.at n=5A037575
- k th digit of a(n) = number of different digits within 2 places of k (not including k).at n=20A039987
- a(n) is the smallest palindrome > a(n-1) such that a(1)+a(2)+...+a(n) is a prime.at n=35A051934
- n times pi(n) is a palindrome, where pi(n) = PrimePi(n) = A000720(n).at n=41A116054
- Numbers for which the sum of reciprocals of square of digits is an integer.at n=19A182452
- List of imprimitive words over the alphabet {1,2}.at n=17A213972
- Squares in the Thue-Morse word A001285.at n=5A225186
- Shortest (x+1,2x)-code of n.at n=25A233135
- Reversed shortest (x+1,2x)-code of n.at n=25A233137
- List of privileged words over the alphabet {1,2}.at n=25A235609
- Triangle read by rows: number of (1-2-3)-avoiding permutations on n letters with k peaks.at n=55A236406
- Non-primitive words on {1,2,3}.at n=31A239018
- a(n) is the largest integer with n digits in base 3/2.at n=5A304024
- Palindromes with exactly 5 distinct prime divisors.at n=24A373465
- List of palindromic subwords (or palindromic factors) of the Kolakoski sequence (A000002).at n=11A376688