86214
domain: N
Appears in sequences
- a(n) = a(n-1) + 7*a(n-2) for n >= 2, a(0)=1, a(1)=2.at n=10A133469
- Base-2 logarithm of (n-th even superperfect number divided by 2^n).at n=27A134712
- Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} having k doubledescents (0 <= k <= n-2). We say that i is a doubledescent (also called a double fall) of a permutation p if p(i) > p(i+1) > p(i+2).at n=32A162975
- Number of permutations of [n] with exactly two (possibly overlapping) occurrences of the consecutive step pattern {up}^2.at n=9A230621