21352

Appears in sequences

• Numbers whose sum of the squares of divisors is also a square number.at n=13A046655
• a(n) = smallest multiple of prime(n) such that a(n) +1 is a multiple of prime(n+1).at n=36A077338
• Number of base 16 circular n-digit numbers with adjacent digits differing by 7 or less.at n=4A125428
• Molecular topological index of the n-antiprism graph.at n=16A192791
• Sophie Germain 5-almost primes.at n=44A211162
• Lengths of binary representations of prime Fibonacci numbers.at n=28A215367
• Number of partitions of n in which no parts are multiples of 6.at n=40A219601
• a(n) = n*(n^2 + 3*n - 2)/2.at n=34A256857
• 40-gonal numbers: a(n) = 38*n*(n-1)/2 + n.at n=34A261191
• Number of cyclic subgroups of the group C_n x C_n x C_n x C_n, where C_n is the cyclic group of order n.at n=19A280184
• Expansion of 1 / (1 - 2 * Sum_{k>=1} x^(k^2)).at n=13A329971
• Expansion of e.g.f. exp(x * (3 + exp(x))).at n=6A367875