26730

Appears in sequences

• Number of 4's in all partitions of n.at n=38A024788
• Expansion of 1/(1-3*x)^8; 8-fold convolution of A000244 (powers of 3).at n=4A036221
• Composite numbers divisible by the palindromic sum of their palindromic prime factors (counted with multiplicity).at n=23A046366
• A convolution triangle of numbers obtained from A025751.at n=11A049224
• Smallest number which has more different digits than its n-th power, or -1 if no such number exists.at n=2A061724
• First differences of (n+1)^5-n^5.at n=10A068236
• Engel expansion of sinh(1/3).at n=27A068380
• a(1)=1; thereafter, a(n+1) = 20*n^3 + 10*n.at n=11A101098
• a(n) = 3^4 * binomial(n+3, 4).at n=7A102741
• Numbers of the form p^5*q*r*s where p, q, r, and s are distinct primes.at n=34A179704
• G.f.: Sum_{n>=0} (2*n)! * x^n / Product_{k=1..2*n} (1 + k*x).at n=4A208885
• Averages y of twin prime pairs that satisfy y = x^2 + x - 2.at n=13A214840
• Numbers n having at least two distinct symmetrical pairs of divisors (a, b) and (b', a') such that n = a*b = b'*a' with a' = reverse(a) and b' = reverse(b).at n=40A228164
• a(n) is the smallest k such that the sum of squares of prime divisors of k is equal to the sum of prime divisors of n+k.at n=34A228182
• Number of n X 2 0..2 arrays with horizontal differences mod 3 never 1, vertical differences mod 3 never -1, rows lexicographically nondecreasing, and columns lexicographically nonincreasing.at n=25A229422
• Numbers k such that k is the average of four consecutive primes k-7, k-1, k+1 and k+7.at n=26A258879
• Numbers k such that k is a multiple of A005941(k).at n=53A364550
• Number of permutations p of [n] whose fixed points j < n have a larger right neighbor p(j+1) > j.at n=8A371800
• Ulam numbers sandwiched between twin prime numbers.at n=38A380429
• G.f. A(x) satisfies A(x) = 1 + x*(1+x^3)^3*A(x)^2.at n=10A389874