21155

Appears in sequences

• Every prefix prime in base 6 (written in base 6).at n=22A024766
• Indices of primes in sequence defined by A(0) = 33, A(n) = 10*A(n-1) - 7 for n > 0.at n=5A056252
• n*10^4-1, n*10^4-3, n*10^4-7 and n*10^4-9 are all prime.at n=4A064978
• Structured meta-anti-prism numbers, the n-th number from a structured n-gonal anti-prism number sequence.at n=14A100185
• a(n) = A120020(n)/n = coefficient of x^n in the n-th self-composition of the g.f. of A120010, divided by n, for n>=1.at n=6A120022
• Number of (w,x,y) with all terms in {0,...,n} and x != min(|w-x|, |x-y|).at n=27A213502
• The expansion of R(q)^-5 in powers of q where R() is the Rogers-Ramanujan continued fraction.at n=33A229793
• a(n) = Sum_{i=0..n} digsum_5(i)^4, where digsum_5(i) = A053824(i).at n=37A231671
• Number of partitions p of n such that (number of even numbers in p) is a part of p.at n=39A241544
• Triangular array read by rows: T(n,k) is the number of transitive relations on {1,2,...,n} that have exactly k reflexive points, n>=0, 0<=k<=n.at n=16A245767
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 627", based on the 5-celled von Neumann neighborhood.at n=26A273276