42630

Appears in sequences

• Number of 2n-bead balanced binary strings of fundamental period 2n, rotationally equivalent to reverse, complement and reversed complement.at n=21A045665
• Triangle read by rows: T(n,c) = number of successive equalities in set partitions of n.at n=59A056857
• a(n) = (n/2)*(n + 1)*(3*n + 11).at n=28A059997
• Number of partitions of {1...n} containing 4 pairs of consecutive integers, where each pair is counted within a block and a string of more than 2 consecutive integers are counted two at a time.at n=6A105481
• Each term is the previous term times the number of letters in the previous number, as conventionally spelled out in English.at n=5A129731
• a(n) = A130179(n)/81.at n=30A130085
• Triangular array read by rows: T(n,k) is the number of blocks of size k in all set partitions of {1,2,...,n}.at n=48A175757
• Numbers whose Euler totient is the reverse of the sum of its aliquot parts.at n=4A247080
• Unitary practical numbers that are nonsquarefree.at n=31A287173
• Number of (undirected) paths in the n-helm graph.at n=13A292001
• Numbers k such that N = k^6 is a twin rank (cf. A002822: 6N +- 1 are twin primes).at n=17A326236
• Primitive terms of A051487.at n=23A346694
• a(n) = Sum_{k=1..n} k * sigma_2(k).at n=18A356125