8288280

Appears in sequences

• Four numbers (a,b,c,d) with a<b<c<d that satisfy sigma(a) = sigma(b) = sigma(c) = sigma(d) = a+b+c+d are called an amicable quadruple. We order these quadruples according to the common value of sigma. The values of (a, b, c, d, sigma) are in (this sequence, A036472, A036473, A036474, A116148) respectively.at n=19A036471
• Partial sums of A050405.at n=21A052206
• Least k > 0 such that t^k = 1 mod (prime(n) - t) for 0 < t < prime(n).at n=16A066220
• Numbers that can be expressed as the difference of the squares of primes in exactly nineteen distinct ways.at n=10A092015
• Triangle T(n, k) = (binomial(n,2))! / (k! * abs(k+1 - binomial(n,2))!), read by rows.at n=34A123146
• a(n) = denominator of sum of the reciprocals of all terms in rows 1 through n of table A126336.at n=11A126339
• Smallest number having exactly n triangular divisors.at n=34A130317
• Smallest number m with property that 2^m-1 is divisible by first n odd primes.at n=14A155747
• a(n) is the last defined element in the sequence n, f(n), f(f(n)), ..., where f(t) = lcm(t,(b+c)/2) with b < c smallest consecutive divisors of t with c - b > 1 and f(t) is undefined if such b, c do not exist or b + c is odd.at n=22A206034
• Number T(n,k) of 2n-length strings of balanced parentheses of exactly k different types; triangle T(n,k), n>=0, 0<=k<=n, read by rows.at n=39A256061
• a(n) = (25*n + 41)*Pochhammer(n, 5) / 6!.at n=23A293611
• a(n) is the multiplicative order of the n-th prime number q modulo (q-1)#.at n=16A333992
• Noncubefree numbers k such that A073185(k) > 2*k.at n=25A357700
• a(n) = n * binomial(4*n, n).at n=7A378802