1221121

Appears in sequences

• Successive generations of the Kolakoski sequence A000002.at n=3A054351
• Numbers that eventually reach 1 under "x -> sum of 5th power of digits of x".at n=24A219112
• The decimal expansion of a(n) is the first n terms of A000002.at n=7A329360
• The word 1 belongs to the sequence, and whenever a word w belongs to the sequence, then the words consisting of 1's and 2's whose run lengths transform equals w also belong to the sequence.at n=32A376637