72662

Appears in sequences

• Numbers k such that k*3^k - 1 is prime.at n=16A006553
• Numbers k such that gpf(k^2+1)/k sets a new record of low value, where gpf(k) is the greatest prime dividing k (A006530).at n=25A173561
• Number of n X 2 0..2 arrays with no element equal the average of immediate neighbors vertically above and horizontally left of it.at n=6A208439
• Number of nX7 0..2 arrays with no element equal the average of immediate neighbors vertically above and horizontally left of it.at n=1A208444
• T(n,k)=Number of nXk 0..2 arrays with no element equal the average of immediate neighbors vertically above and horizontally left of it.at n=29A208445
• T(n,k)=Number of nXk 0..2 arrays with no element equal the average of immediate neighbors vertically above and horizontally left of it.at n=34A208445
• Numbers n such that n^2 + 1 can be expressed as j^2 + k^2, j > k > 1, in more ways than for any smaller n.at n=14A300161
• Numbers n such that n^2+1 can be expressed as j^2+k^2, j>k>1, gcd(j,k)=1, in more ways than for any smaller n.at n=5A300167
• Sum of all the parts in the partitions of n into 9 squarefree parts.at n=47A326523
• Irregular triangle read by rows. For each j, 1<=j<=n properly color the vertices of a labeled graph on [n] using each of the first j colors in the color set {c1<c2<...<cn}. Orient the edges according to the strict order on the colors. T(n,k) is the number of such directed graphs containing k descents, n>=0, 0<=k<=binomial(n,2).at n=17A381102