56980

Appears in sequences

• S2(j,2j+3) where S2(n,k) is a 2-associated Stirling number of the second kind.at n=3A000504
• Triangle T(n,k) of associated Stirling numbers of second kind, n >= 2, 1 <= k <= floor(n/2).at n=28A008299
• Even square pyramidal numbers.at n=26A015222
• Number of ways of placing n labeled balls into 4 indistinguishable boxes with at least 2 balls in each box.at n=3A058844
• Accumulative sum of the greatest digit of n minus the least digit of n (A037904) <= 10^n.at n=3A072817
• Expansion of (1-x)^(-1)/(1-3*x-3*x^2-2*x^3).at n=8A077822
• 75-gonal numbers: a(n) = n*(73*n-71)/2.at n=40A098230
• Structured rhombic dodecahedral numbers (vertex structure 9).at n=27A100157
• Coefficient of x^2 in the polynomial (x-p(n))*(x-p(n+1))*(x-p(n+2))*(x-p(n+3)), where p(k) is the k-th prime.at n=23A127348
• a(0)=0, a(1)=1, a(2)=5 and for n>2: a(n) = a(n-1)*(a(n-1) + 1)*(2*a(n-1) + 1)/6.at n=4A129440
• Triangle of Ward numbers T(n,k) read by rows.at n=24A134991
• Triangle read by rows, T(n,k) = (-1)^k*{{n,k}} where {{n,k}} are the second-order Stirling set numbers, n>=0, 0<=k<=n/2.at n=40A137375
• Triangle of Ward numbers T(n,k) (n>=0, k=0 if n=0, otherwise 0 <= k <= n-1) read by rows.at n=25A181996
• Number of blocks in a Steiner Quadruple System of order A047235(n+1).at n=36A228124
• Consider a number of k digits n = d_(k)*10^(k-1) + d_(k-1)*10^(k-2) + … + d_(2)*10 + d_(1). Sequence lists the numbers n such that phi(n) = Sum_{i=1..k-1}{sigma(Sum_{j=1..i}{d_(j)*10^(j-1)})} (see example below).at n=9A240897
• Triangle read by rows, Ward numbers T(n, k) = Sum_{m=0..k} (-1)^(m + k) * binomial(n + k, n + m) * Stirling2(n + m, m), for n >= 0, 0 <= k <= n.at n=32A269939
• Doubly square pyramidal numbers.at n=5A329753
• Regular triangle read by rows. T(n, k) = {{n, k}}, where {{n, k}} are the second order Stirling set numbers (or second order Stirling numbers). T(n, k) for 0 <= k <= n.at n=70A358623
• Irregular table read by rows: T(n,k) is the number of k-gons, k>=2, in the Farey Ring graph FR(n) defined in A359116.at n=56A359119
• Least number m such that 9*k*m+1 is prime for k=1..n.at n=6A372238