30064771072
domain: N
Appears in sequences
- a(n) = 7*4^n.at n=16A002042
- Denominators of Taylor series expansion of arcsin(x). Also arises from arccos(x), arccsc(x), arcsec(x), arcsinh(x).at n=17A002595
- Fourth column of triangle A067402.at n=9A067404
- G.f.: Sum_{n>=0} (n+1)*(n+2)/2 * 2^(n*(n-1)) * x^n.at n=6A202944
- Expansion of (1 + 2*x)^2/(1 - 2*x)^2.at n=28A241204
- Denominators of coefficients of z^n for the expansion of Fricke's hypergeometric function F_1(1/2,1/2;z).at n=8A274656
- Smaller member of a noninfinitary amicable pair: numbers (k, m) such that nisigma(k) = m and nisigma(m) = k, where nisigma(k) is the sum of the noninfinitary divisors of k (A348271).at n=10A348343
- a(n) is the least number with n prime factors (counted with multiplicity) that is the concatenation of two primes.at n=32A374669