19208

Appears in sequences

• Numbers of form 2^i*7^j, with i, j >= 0.at n=46A003591
• Expansion of g.f.: (1+x)/(1-7*x).at n=5A003950
• Place n equally-spaced points around a circle and join every pair of points by a chord; this divides the circle into a(n) regions.at n=27A006533
• a(n) = floor(n/5)*floor((n+1)/5)*floor((n+2)/5)*floor((n+3)/5)*floor((n+4)/5).at n=36A008382
• Triangle of coefficients in expansion of (1+7x)^n.at n=39A013614
• Denominator of sum of -4th powers of divisors of n.at n=13A017672
• Place n distinguishable balls in n boxes (in n^n ways); let f(n,k) = number of ways that max in any box is k, for 1<=k<=n; sequence gives triangle of numbers f(n,k)/n.at n=32A019576
• Number of partitions of n into parts of 4 kinds.at n=11A023003
• a(1) = 3; a(n+1) = a(n)-th nonprime, where nonprimes begin at 1.at n=39A025004
• Duplicate of A036566.at n=16A025630
• Triangle whose (i,j)-th entry is binomial(i,j)*7^(i-j).at n=41A027466
• Numbers whose prime factors are 2 and 7.at n=26A033847
• Coordination sequence for lattice D*_98 (with edges defined by l_1 norm = 1).at n=2A035834
• Coordination sequence for diamond structure D^+_98. (Edges defined by l_1 norm = 1.)at n=2A035925
• Triangle of numbers in which i-th row is {2^(i-j)*7^j, 0<=j<=i}; i >= 0.at n=32A036565
• Numbers of form 7^i*8^j with i, j >= 0, sorted.at n=16A036566
• Sums of 2 distinct powers of 7.at n=14A038481
• Gaps of 8 in sequence A038593 (lower terms).at n=13A038655
• Numbers whose base-7 representation contains exactly four 0's.at n=30A043396
• a(n) = floor(a(n-1)/2) if this is positive and not yet in the sequence, otherwise a(n) = 7*a(n-1).at n=42A050012