81147

Appears in sequences

• Reversion of partitions into distinct parts A000009.at n=14A050393
• Number of doubletons in all partitions of n. By a doubleton in a partition we mean an occurrence of a part exactly twice (the partition [4,(3,3),2,2,2,(1,1)] has two doubletons, shown between parentheses).at n=45A116646
• a(n) = number of distinct words arising in Post's tag system {00, 1101} applied to the word (100)^n , or a(n) = -1 if this word has an unbounded trajectory.at n=35A302202