50820

Appears in sequences

• Theta series of A*_10 lattice.at n=42A023922
• Product of numerator and denominator of the n-th harmonic number, 1 + 1/2 + 1/3 +...+ 1/n.at n=6A064167
• Values of m such that N=(am+1)(bm+1)(cm+1) is a 3-Carmichael number (A087788), where a,b,c = 1,2,51.at n=14A064262
• Let s(k) denote the k-th term of an integer sequence such that s(0)=0 and s(i) for all i>0 is the least natural number such that no four elements of {s(0),..,s(i)} are in arithmetic progression. Then it appears that there are many set of 3 consecutive integers in s(k). Sequence gives the smallest element in those triples.at n=34A071711
• Number of singular n X n rational {0,1}-matrices with no zero rows or columns and with all rows distinct, up to permutation of rows.at n=4A116532
• Generalized Narayana numbers, T(n, k) = 3/(n + 1)*binomial(n + 1, k + 2)*binomial(n + 1, k - 1), triangular array read by rows.at n=48A145597
• Numbers with exactly 5 distinct prime divisors {2,3,5,7,11}.at n=18A147572
• Numbers with prime factorization pqrs^2t^2.at n=28A189989
• The smallest number beginning with n whose distinct prime factors are the first n primes.at n=4A225903
• Self-inverse permutation of nonnegative integers, A075158-conjugate of the inverse of gray code: a(n) = 1 + A075157(A006068(A075158(n-1))).at n=57A245452
• Sum over all partitions of n of the number of distinct parts i of multiplicity i.at n=47A276428
• Number of minimum total dominating sets in the n X n grid graph.at n=24A303142
• a(n) = A025487(n) * A324576(n) = A025487(n) * A276086(A025487(n)).at n=28A324577
• a(n) = A108951(n) * A276086(A108951(n)).at n=13A324887
• Numbers n for which 2 < A257993(A276086(A276086(n))) < A257993(n), where A276086 converts the primorial base expansion of n into its prime product form, and A257993 returns the index of the least prime not present in its argument.at n=34A328762
• One-third of the number of simple intersection points in the interior of the n-th triangle described in A092867 and A366479.at n=17A366480
• Expansion of 1/((1-3*x) * (1-7*x))^(5/2).at n=4A387283