20550

Appears in sequences

• Number of extreme points of the set of n X n symmetric doubly-substochastic matrices.at n=7A006848
• a(n) = number of (s(0), s(1), ..., s(n)) such that every s(i) is an integer, s(0) = 0 = s(n), |s(i) - s(i-1)| = 1 for i = 1,2,3; |s(i) - s(i-1)| <= 1 for i >= 4. Also a(n) = T(n,n), where T is the array defined in A026082.at n=8A026083
• Denominators of continued fraction convergents to sqrt(829).at n=12A042601
• Number of nonnegative solutions of x1^2 + x2^2 + ... + x10^2 = n.at n=21A045852
• a(n) = 60*n^2 + 180*n + 150.at n=16A069477
• Triangle T(n,k) read by rows, where o.g.f. for T(n,k) is n!*Sum_{k=0..n} (1+x)^(n-k)/k!.at n=23A073474
• Third differences of fifth powers (A000584).at n=19A101096
• a(n) is a non-palindromic composite located between twin primes whose reverse, which is less than it, is also located between twin primes.at n=14A103741
• Average of twin-prime pairs for pairs that are expressible as the sum of two triangular numbers.at n=38A117313
• Numbers k such that k and k^2 use only the digits 0, 2, 3, 4 and 5.at n=41A136882
• Numbers k such that k^2 + 1 == 0 (mod 41^2).at n=24A157116
• Number of length 5 nonnegative integer arrays starting and ending with 0 with adjacent elements unequal but differing by no more than n.at n=24A205342
• Number of nX7 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 0 1 and 0 1 0 vertically.at n=2A207425
• T(n,k)=Number of nXk 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 0 1 and 0 1 0 vertically.at n=38A207426
• Number of 3Xn 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 0 1 and 0 1 0 vertically.at n=6A207427
• Number of nX7 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 0 1 and 1 0 0 vertically.at n=2A207740
• T(n,k)=Number of nXk 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 0 1 and 1 0 0 vertically.at n=38A207741
• Averages q of twin prime pairs, such that q concatenated to q is also the average of a twin prime pair.at n=26A235109
• Numbers n such that for some m, A166133(m)=n, A166133(m+1)=n^2-1, in order of increasing m.at n=35A256406
• Numbers n such that for some m, A166133(m)=n, A166133(m+1)=n^2-1, in increasing order.at n=34A256407