20973

Appears in sequences

• Expansion of 1/(1-x^4-x^5-x^6-x^7-x^8-x^9-x^10-x^11).at n=38A017833
• Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 96.at n=37A031594
• Numbers k such that 143*2^k+1 is prime.at n=7A032421
• McKay-Thompson series of class 31A for Monster.at n=39A058628
• Numbers k such that k and 5*k, taken together, are pandigital.at n=16A115925
• Write 0, 1, ..., n in base 3 and add as if they were decimal numbers.at n=43A121718
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 0, -1), (1, -1, 1), (1, 1, -1), (1, 1, 1)}.at n=8A149627
• Row 5 of A277710: Positions of 5's in A264977; positions of 10's in A277330.at n=40A277715
• Number T(n,k) of set partitions of [n] such that the maximal absolute difference between consecutive elements within a block equals k; triangle T(n,k), n>=0, 0<=k<=max(n-1,0), read by rows.at n=50A287213
• Number of set partitions of [n] such that the maximal absolute difference between consecutive elements within a block equals four.at n=5A294053
• Let b(1) = 2 and let b(n+1) be the least prime expressible as k*(b(n)-1)*b(n)+1; this sequence gives the values of k in order.at n=18A339174
• G.f. A(x) satisfies A(x) = 1 / ((1 - x) * (1 - 2 * x * A(x^3))).at n=11A390660