30660

Appears in sequences

• a(1) = 5; a(n+1) = a(n)-th nonprime, where nonprimes begin at 4.at n=41A025010
• 4th level triangle related to Eulerian numbers and binomial transforms (A062254 is third level, A062253 is second level, triangle of Eulerian numbers is first level and triangle with Z(0,0)=1 and Z(n,k)=0 otherwise is 0th level).at n=16A062255
• Nonnegative values x of solutions (x, y) to the Diophantine equation x^2+(x+343)^2 = y^2.at n=20A118611
• Triangle read by rows: row n is the first row of the matrix M[n]^(n-1), where M[n] is the n X n tridiagonal matrix with main diagonal (3,4,4,...) and super- and subdiagonals (1,1,1,...).at n=50A124574
• Number of Lyndon words on {1,2,3} with an even number of 1's and an even number of 2's.at n=12A136703
• Number of Lyndon words on {1,2,3} with an odd number of 1's and an odd number of 2's.at n=12A136704
• Numbers n such that phi(n)=d_1!!*d_2!!*...*d_k!! where d_1 d_2 ... d_k is the decimal expansion of n.at n=20A139408
• First differences of harmonic (or Ore) numbers A001599.at n=27A153789
• A partition product of Stirling_1 type [parameter k = 3] with biggest-part statistic (triangle read by rows).at n=31A157393
• a(n) = 1225*n^2 + 35.at n=5A158733
• a(n) = 25*n^2 + n.at n=34A173089
• Triangle given by p(n,k)=(coefficient of x^(n-k) in (1/2) ((x+3)^n+(x+1)^n)), 0<=k<=n.at n=48A193673
• Smallest number k such that k^n is the sum of numbers in a twin prime pair.at n=49A195336
• Number of (n+1)X(1+1) 0..3 arrays colored with the maximum plus the upper median minus the lower median of every 2X2 subblock.at n=2A236124
• Number of (n+1) X (3+1) 0..3 arrays colored with the maximum plus the upper median minus the lower median of every 2 X 2 subblock.at n=0A236126
• T(n,k)=Number of (n+1)X(k+1) 0..3 arrays colored with the maximum plus the upper median minus the lower median of every 2X2 subblock.at n=3A236127
• T(n,k)=Number of (n+1)X(k+1) 0..3 arrays colored with the maximum plus the upper median minus the lower median of every 2X2 subblock.at n=5A236127
• Numbers n with the property that it is possible to write the base 2 expansion of n as concat(a_2,b_2), with a_2>0 and b_2>0 such that, converting a_2 and b_2 to base 10 as a and b, we have antisigma(a) + antisigma(b) = n.at n=10A259670
• a(n) = (1/2)*(n + 1)*(5*n^2 + 15*n + 6)*Pochhammer(n, 6) / 6!.at n=4A293612
• Numbers k such that the largest prime divisor of k^4+1 is less than k.at n=42A309562