25271

Appears in sequences

• a(n) = prime(n)*prime(n+1) - prime(n) - prime(n+1).at n=36A037165
• Numbers that define integer Heronian triangles [prime(a(n)), prime(a(n)+1), A068965(n)] with area A068966(n).at n=24A068964
• Nonprime numbers k such that (k+1)*Sum_{d|k} 1/(d+1) is an integer.at n=16A069155
• Odd numbers k such that (10^k - 1)/3 - 2*10^floor(k/2) is a palindromic wing prime (a.k.a. near-repdigit palindromic prime) of the form 3...313...3.at n=18A077775
• Write down the numbers from 3 to infinity. Take next number, M say, that has not been crossed off. Counting through the numbers that have not yet been crossed off after that M, cross off every 5th term. Repeat, always crossing off every 5th term of those that remain. The numbers that are left form the sequence.at n=41A100586
• a(n) = 4*n^3 - 6*n^2 + 1.at n=19A141530
• a(n) = (n+3)^2*n/2 + 1.at n=35A154560
• a(n) = 70*n^2 + 1.at n=19A158734
• a(n) = 78*n^2 - 1.at n=17A158771
• Fixed points of A275957; numbers n for which A060125(n) = A225901(n).at n=52A275843
• Coefficients in the expansion of 1/([r]-[2*r]*x+[3*r]*x^2-...); [ ]=floor, r=-1+sqrt(7).at n=17A288234
• Number of nX3 0..1 arrays with every element unequal to 1, 2, 3, 4, 7 or 8 king-move adjacent elements, with upper left element zero.at n=6A316578
• Number of nX7 0..1 arrays with every element unequal to 1, 2, 3, 4, 7 or 8 king-move adjacent elements, with upper left element zero.at n=2A316582
• T(n,k)=Number of nXk 0..1 arrays with every element unequal to 1, 2, 3, 4, 7 or 8 king-move adjacent elements, with upper left element zero.at n=38A316583
• T(n,k)=Number of nXk 0..1 arrays with every element unequal to 1, 2, 3, 4, 7 or 8 king-move adjacent elements, with upper left element zero.at n=42A316583
• a(n) = Sum_{d|n} d*binomial(d+2,3).at n=18A321598
• Number of compositions (ordered partitions) of n into at most 6 nonprime parts.at n=41A347799
• Row sums of A352369.at n=7A352370