211000

Appears in sequences

• a(n) = Sum_{k = 1..n} floor(2^k / k).at n=20A000801
• Numbers n such that phi(reversal(n)) = reversal(phi(n)). Ignore leading 0's.at n=31A069282
• Ternary numbers consisting of a run of 2's, then a run of 1's, then a run of 0's.at n=11A371053
• Ternary numbers that are concatenated runs C(1)A(1)B(1)C(2)A(2)B(2)...C(k)A(k)B(k), where A(i) is a run of 1's, B(i) a run of 0's, and C(i) a run of 2's, for i = 1..k.at n=12A371111
• Modified Sisyphus function of order 5: a(n) is the concatenation of the number of digits in n with the number of digits of n congruent to k modulo 5 for each k from 0 to 4 in turn.at n=10A375208
• Modified Sisyphus function of order 5: a(n) is the concatenation of the number of digits in n with the number of digits of n congruent to k modulo 5 for each k from 0 to 4 in turn.at n=15A375208