121121121

Appears in sequences

• Smallest natural number requiring n words in English (as spoken in England).at n=16A001167
• Decimal expansion of a(n) is given by the first n terms of the periodic sequence with initial period 1,2,1.at n=8A037543
• a(n) = n base 5, under morphism f(1) = 121, f(2) = 123, f(3) = 141, f(4) = 142, or 0 if n base 5 has a zero.at n=30A137850
• Smallest positive integer whose American English name consists of n words.at n=13A356738