57057

Appears in sequences

• a(n) = number of (s(0), s(1), ..., s(n)) such that s(i) is a nonnegative integer and |s(i) - s(i-1)| <= 1 for i = 1,2,...,n, s(0) = 2, s(n) = 4. Also a(n) = T(n,n-2), where T is the array in A026323.at n=10A026327
• Odd numbers with exactly 5 distinct prime factors.at n=27A046391
• A class of Boolean functions of n variables and rank 3.at n=13A051361
• Number of primitive (period n) step cyclic shifted sequences using exactly three different symbols.at n=13A056425
• a(n) is both the sum of n+1 consecutive integers and the sum of the n immediately higher consecutive integers.at n=38A059270
• One half of sixth column (m=5) of triangle A060556.at n=6A060559
• Multiples of 1729, the Hardy-Ramanujan number.at n=33A138129
• a(n) = sqrt(sigma(2*m^2)), where m = A097023(n), i.e., sigma(2*m^2) is a square.at n=6A163764
• Products of 5 distinct primes a,b,c,d,e, such that a+b+c+d+e are prime numbers.at n=6A178782
• -3-Knödel numbers.at n=42A225507
• Numbers n such that phi(n) = phi(n+11), with Euler's totient function phi = A000010.at n=34A276504
• a(n) = (25*n + 41)*Pochhammer(n, 5) / 6!.at n=9A293611
• a(n) = n*(2*n + 1)*(4*n + 1).at n=19A316224
• Numbers k satisfying gcd(k^2, sigma(k^2)) > sigma(k), where sigma is the sum-of-divisors function.at n=27A322154
• Denominators of the Faulhaber polynomials.at n=38A335952
• a(n) is the smallest number that has exactly n odious divisors (A000069).at n=18A355968
• Numbers k such that 5*k+1 divides 5^k+1.at n=3A381256
• Primitive cubic pyritohedral numbers: a(n) = 864*n^3 - 2484*n^2 + 2384*n - 763.at n=4A391165