137257

Appears in sequences

• a(n) = (p^p-1)/(p-1) where p = prime(n).at n=3A001039
• Cyclotomic polynomials at x=7.at n=7A019325
• Strong pseudoprimes to base 7.at n=23A020233
• Strong pseudoprimes to base 26.at n=30A020252
• Cyclotomic polynomials at x = -7.at n=14A020506
• Triangle of Gaussian binomial coefficients [ n,k ] for q = 7.at n=29A022171
• Triangle of Gaussian binomial coefficients [ n,k ] for q = 7.at n=34A022171
• Gaussian binomial coefficients [ n,6 ] for q = 7.at n=1A022235
• a(n) = (7^n - 1)/6.at n=7A023000
• a(n) = n^0 + n^1 + ... + n^(n-1), or a(n) = (n^n-1)/(n-1) with a(0)=0; a(1)=1.at n=7A023037
• Number of sublattices of index n in generic 7-dimensional lattice.at n=6A038994
• Numbers that are repdigits in base 7.at n=37A048332
• a(n) = 1111111 in base n.at n=6A053716
• Period of the sequence of Bell numbers A000110 (mod n).at n=6A054767
• a(n) = floor(7^7/n).at n=5A057069
• Zsigmondy numbers for a = 7, b = 1: Zs(n, 7, 1) is the greatest divisor of 7^n - 1^n (A024075) that is relatively prime to 7^m - 1^m for all positive integers m < n.at n=6A064083
• Z(S_m; sigma[1](n), sigma[2](n),..., sigma[m](n)) where Z(S_m; x_1,x_2,...,x_m) is the cycle index of the symmetric group S_m and sigma[k](n) is the sum of k-th powers of divisors of n; m=6.at n=6A068023
• Value of n-th cyclotomic polynomial at n.at n=6A070518
• Numbers of the form (7^{mr}-1)/(7^r-1) for positive integers m, r.at n=14A076286
• Triangle read by rows: T(n,k) = (n+1,k)-th element of (M^7-M)/6, where M is the infinite lower Pascal's triangle matrix, 1<=k<=n.at n=21A096041