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).
A116646
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).
Terms
- a(0) =0a(1) =0a(2) =1a(3) =0a(4) =2a(5) =2a(6) =4a(7) =5a(8) =10a(9) =11a(10) =20a(11) =25a(12) =38a(13) =49a(14) =73a(15) =91a(16) =131a(17) =167a(18) =228a(19) =291a(20) =392a(21) =493a(22) =653a(23) =822a(24) =1065a(25) =1336a(26) =1714a(27) =2131a(28) =2706a(29) =3354
External references
- oeis: A116646