25365

Appears in sequences

• a(n) = Sum_{k=1..n-1} k*sigma(k)*sigma(n-k).at n=18A000441
• 4-dimensional figurate numbers: a(n) = (5*n-1)*binomial(n+2,3)/4.at n=18A002418
• Number of bargraphs of site-perimeter n.at n=20A075126
• Group the natural numbers such that the n-th group sum is divisible by prime(n): (1, 2, 3), (4, 5), (6, 7, 8, 9), (10, 11), (12, 13, 14, 15, 16, 17, 18, 19, 20, 21), ... Sequence contains the sum of the terms in the n-th group.at n=23A086491
• Indices of primes in sequence defined by A(0) = 79, A(n) = 10*A(n-1) - 1 for n > 0.at n=10A101153
• Numbers whose sum of triangular divisors is also a divisor and greater than 1.at n=34A209311
• a(n) = binomial(floor(n/2),4) + (ceiling(n/2)-3)*binomial(floor(n/2),3).at n=41A234277
• 28-gonal pyramidal numbers: a(n) = n*(n+1)*(26*n-23)/6.at n=18A256648
• Number of partitions of n having no perfect cube parts (n>=0).at n=51A264393
• Expansion of x*(1 + 3*x + x^2)/((1 - x)^5*(1 + x)^4).at n=35A287143
• Number of permutations of [n] avoiding {1324, 1342, 3412}.at n=10A294814
• Heinz numbers of integer partitions whose reciprocal sum is 1.at n=17A316855
• Heinz numbers of aperiodic integer partitions into relatively prime parts whose reciprocal sum is 1.at n=9A316888
• Heinz numbers of aperiodic integer partitions whose reciprocal sum is 1.at n=13A316889
• Heinz numbers of integer partitions into relatively prime parts whose reciprocal sum is 1.at n=9A316890
• Heinz numbers of integer partitions into relatively prime parts whose reciprocal sum is the reciprocal of an integer.at n=14A316901
• Smallest positive number for which the 3rd power cannot be written as sum of 3rd powers of any subset of previous terms.at n=52A321290