24381

Appears in sequences

• Expansion of 1/((1-3x)(1-6x)(1-9x)).at n=4A017933
• Numbers k that divide 5^k + 4^k.at n=40A045590
• Number of primitive (period n) periodic palindromes using a maximum of two different symbols.at n=27A056493
• Number of primitive (period n) periodic palindromes using exactly two different symbols.at n=27A056498
• Term at which first number of height n occurs in Recamán's sequence A005132.at n=21A064292
• Values of n at which the ratio A005132(n)/n sets a new record.at n=12A064622
• Stirling2 triangle with scaled diagonals (powers of 3).at n=23A075498
• The following triangle is based on Pascal's triangle. The r-th term of the n-th row is sum of C(n,r) successive integers so that the sum of all the terms of the row is (2^n)*(2^n+1)/2, the 2^n -th triangular number. Sequence contains the triangle read by rows.at n=49A112358
• Riordan array (1/((1-x)(1-3x)),x/((1-x)(1-3x))).at n=50A116414
• b(n)*b(n+1), where b() = A000930().at n=14A170935
• The number of different classes of 2-dimensional convex lattice polytopes having volume n/2 up to unimodular equivalence.at n=43A187015
• Number of permutations (p(1), p(2), ..., p(n)) satisfying -k <= p(i)-i <= r and p(i)-i not in the set I, i=1..n, with k=2, r=4, I={-1,1,2,3}.at n=29A224809
• a(n) = n^3 - 8.at n=29A259348
• Number of nX3 0..1 arrays with every element unequal to 1, 2, 5 or 8 king-move adjacent elements, with upper left element zero.at n=20A304297
• G.f.: Sum_{n>=0} (n+1)*(n+2)*(n+3)*(n+4)/4! * x^n * (1 + x^n)^n.at n=25A326005
• a(n) = A333552(A333551(n)): indices of terms in Recamán's sequence A005132 where the construction avoided a record-sized collision.at n=48A333553
• T(n, k) = Sum_{p in P(n, k)} card(p), where P(n, k) is the set of set partitions of {1,2,...,n} where the largest block has size k and card(p) is the number of blocks of p. Triangle T(n, k) for 0 <= k <= n, read by rows.at n=49A339030