21051

Appears in sequences

• If p(k) is the k-th prime, then the n-th set of 3 consecutive cousin prime pairs starts at p(a(n)).at n=33A095970
• a(n) = Sum_{k=0..floor(n/8)} binomial(n-5*k, 3*k).at n=28A113032
• Sum of squares of three consecutive primes.at n=21A133529
• 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, 1, 0), (0, 0, -1), (0, 0, 1), (1, 0, 1)}.at n=8A150335
• Number of 1-sided snake polyominoes with n cells.at n=13A151514
• Number of 2-sided strip polyrhombs with n cells.at n=13A151524
• Number a(n) of alternative sets of orthogonal contrasts available to partition variation between n levels of a categorical factor in analysis of variance, with each set described by a unique general linear model.at n=13A165438
• Number of (n+1) X 3 0..1 arrays with column and row pair sums b(i,j)=a(i,j)+a(i,j-1) and c(i,j)=a(i,j)+a(i-1,j) nondecreasing in column and row directions, respectively.at n=28A204645
• Number of partitions p = [x(1), ..., x(k)], where x(1) >= x(2) >= ... >= x(k), of n such that max(x(i) - x(i-1)) >= number of distinct parts of p.at n=40A241821
• Number of nonequivalent binary matrices with 4 columns and any number of nonzero rows with n ones in every column up to permutation of rows and columns.at n=8A331720
• Number of Motzkin paths of length n up to reversal.at n=13A378941
• a(n) = Sum_{k=0..floor(n/4)} binomial(2*n-5*k,3*k).at n=14A392404