30271

Properties

Appears in sequences

• Primes of form k^2 - 5.at n=33A028877
• Numbers k such that 13^k - 12^k is prime.at n=9A062579
• Number of squares in an n X n grid of squares with diagonals.at n=30A111500
• a(n) is the largest prime < 7*a(n-1) for n > 1, with a(1) = 2.at n=5A126035
• Totally multiplicative sequence with a(p) = a(p-1) + 10 for prime p.at n=30A166707
• Sums of 4 distinct primorials.at n=22A177709
• Larger of emirp pairs whose digital sums are also emirps (A178091).at n=35A178093
• a(n) equals the least sum of the squares of the coefficients in ((1 + x^k)^2 + x^p)^n found at sufficiently large p for some fixed k>0.at n=4A186378
• Number of nX3 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 0,2,1,1,1 for x=0,1,2,3,4.at n=10A197884
• Primes of the form 9n^2 - 5.at n=11A201960
• Number of (n+1)X(n+1) -6..6 symmetric matrices with every 2X2 subblock having sum zero and one or three distinct values.at n=9A211255
• Number of partitions of n into exactly 4 different parts with distinct multiplicities.at n=43A212115
• Primes that can be generated by the concatenation in base 7, in descending order, of two consecutive integers read in base 10.at n=24A287309
• Solution of the complementary equation a(n) = a(n-1) + a(n-2) + b(n-2)*b(n-1)*b(n), where a(0) = 2, a(1) = 4, b(0) = 1, b(1) = 3, b(2) = 5, and (a(n)) and (b(n)) are increasing complementary sequences.at n=11A296282
• Numbers obtained by reinterpreting base-2 representation of odd numbers in primorial base.at n=44A328462
• Emirps p such that if q is the next emirp after p, 2*q-p is also an emirp.at n=28A350852
• Prime numbersat n=3274