18675

Appears in sequences

• Expansion of Product_{m>=1} (1 + m*q^m)^3.at n=11A022631
• a(n) = (1/2)*(n+1)!*Sum_{k=0..floor(n/2)} n^(2k+1)/(2k+1)!.at n=5A046706
• Numbers k such that 4*k-1, 8*k-1, 16*k-1 and 32*k-1 are all primes.at n=11A101794
• Where records occur in A129385.at n=11A129387
• Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 0100-1111-0100 pattern in any orientation.at n=16A146377
• Number of base-3 pyramids of height n.at n=22A186507
• Coefficient of x in the reduction by x^2->x+1 of the polynomial p(n,x) defined below in Comments.at n=17A192762
• Number of integer partitions of n such that every set of distinct parts has a different sum.at n=48A325862
• a(n) = A068346(A276086(n)), where A068346 is the second arithmetic derivative, and A276086 is the primorial base exp-function.at n=56A370131