24921

Appears in sequences

• a(n) = (2*n+1)*(10*n+1).at n=35A033574
• Numbers k such that Sum_{d|k} sigma(d)/d is an integer.at n=5A068986
• Numbers k such that phi(k-1) + phi(k+1) = sigma(k)/2.at n=4A076648
• a(2*n+1) = 7*a(n), a(2*n+2) = 8*a(n) + a(n-1).at n=34A116554
• Numerator of the continued fraction convergents of the decimal concatenation of the Fibonacci numbers.at n=4A128871
• Numbers k such that k^6 - 2 and k^6 + 2 are both primes.at n=34A154938
• Numbers a = b + c where a, b, and c contain the same decimal digits.at n=31A203024
• Number of nX5 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 0 1 and 1 0 1 vertically.at n=8A207021
• a(n) = Sum_{i=0..n} digsum_9(i)^3, where digsum_9(i) = A053830(i).at n=53A231686
• a(n) = Sum_{i=0..n} digsum(i)^3, where digsum(i) = A007953(i).at n=53A231688
• Triangle read by rows: T(n,k) is the number of n-tuples with sum k + n whose i-th element is a positive integer <= prime(i), 0 <= k < A070826(n).at n=67A239738
• Number of nX7 binary arrays with rows and columns lexicographically nondecreasing and row and column sums nonincreasing.at n=8A266546
• Odd composite integers m such that A000045(3*m-J(m,5)) == 1 (mod m), where J(m,5) is the Jacobi symbol.at n=33A340235
• a(0) = 1; a(n) = Sum_{k=0..n-1} (k+1) * binomial(k+3,3) * binomial(n-1,k) * a(k) * a(n-1-k).at n=4A385980