30071

Properties

Appears in sequences

• Numbers k such that k divides the (right) concatenation of all numbers <= k written in base 19 (most significant digit on right).at n=26A061948
• a(1) = 2; a(n) = largest prime not exceeding the sum of all previous terms.at n=15A070805
• Octal representation of the concatenation of the first n decimal numbers with the most significant digits first.at n=4A097583
• Numbers n such that n is prime and is equal to the sum of the first k primes plus the product of the first k primes, for some k.at n=2A120850
• Number of solutions to x/3 + y/4 + z/6 < n with x,y,z>=1 .at n=13A128822
• Numbers such that the digital sum base 2 and the digital sum base 3 and the digital sum base 10 all are equal.at n=28A135120
• Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 110-100-111 pattern in any orientation.at n=10A146174
• Number of n X n binary arrays symmetric about the diagonal and under 90 degree rotation with all ones connected only in a 110-100-111 pattern in any orientation.at n=22A146176
• Number of n X n binary arrays symmetric about the diagonal and under 90 degree rotation with all ones connected only in a 110-100-111 pattern in any orientation.at n=23A146176
• Least prime k such that x' = k has n solutions, where x' is the arithmetic derivative (A003415) of x.at n=30A189559
• Least odd number k such that x' = k has n solutions, where x' is the arithmetic derivative (A003415) of x.at n=30A189560
• Number of nX4 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 4,4,0,0,1 for x=0,1,2,3,4.at n=4A197094
• Number of nX5 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 4,4,0,0,1 for x=0,1,2,3,4.at n=3A197095
• T(n,k)=Number of nXk 0..4 arrays with each element x equal to the number of its horizontal and vertical neighbors equal to 4,4,0,0,1 for x=0,1,2,3,4.at n=31A197098
• T(n,k)=Number of nXk 0..4 arrays with each element x equal to the number of its horizontal and vertical neighbors equal to 4,4,0,0,1 for x=0,1,2,3,4.at n=32A197098
• O.g.f.: Sum_{n>=0} n^n * (1+n*x)^(4*n) * x^n/n! * exp(-n*x*(1+n*x)^4).at n=6A218679
• a(n) = sum_{i=1..n} prime(i) + product_{i=1..n} prime(i).at n=5A228190
• Primes p such that q = p^2 + 10 and q^2 + 10 are also prime.at n=33A243368
• Number of partitions of 6n into exactly 4 parts.at n=27A256328
• P(n,k) is an array read by rows, with n > 0 and k=1..5, where row n gives the chain of 5 consecutive primes {p(i), p(i+1), p(i+2), p(i+3), p(i+4)} having the symmetrical property p(i) + p(i+4) = p(i+1) + p(i+3) = 2*p(i+2) for some index i.at n=18A267028