20091

Appears in sequences

• Base-9 palindromes that start with 3.at n=25A043030
• Numbers n for which there are exactly ten k such that n = k + reverse(k).at n=17A072434
• Pair the odd numbers such that the k-th pair is (r, r+2k) where r is the smallest odd number not included earlier: (1, 3), (5, 9), (7, 13), (11, 19), (15, 25), (17, 29), (21, 35), (23, 39), (27, 45), ... This is the sequence of the product of the members of pairs.at n=34A075320
• Least number beginning with n such that every concatenation is a prime.at n=19A090506
• Numbers k such that 6*k+5, 6*k+11, 6*k+17, 6*k+23 are consecutive primes.at n=21A090836
• 3 times 12-gonal (or dodecagonal) numbers: a(n) = 3*n*(5*n-4).at n=37A153448
• Triangle read by rows of operator ordering coefficients corresponding to the Legendre polynomials L_n(x).at n=16A225694
• Triangle read by rows of operator ordering coefficients corresponding to the Legendre polynomials L_n(x).at n=19A225694
• a(n) = binomial(2*c-1, c-1) (mod c^3), where c is the n-th composite.at n=37A244214
• Expansion of f(x, x^2) * f(x^4, x^8) / f(-x^3, -x^6)^2 in powers of x where f(, ) is Ramanujan's general theta function.at n=50A260183
• Number of North-East lattice paths from (0,0) to (n,n) that bounce off the diagonal y = x to the right exactly four times.at n=6A268402
• Numbers with at least three digits and with the property that the sum of the cubes of the first and last digit equals the number obtained when the first and last digits are deleted.at n=35A275343
• Anagrasum integers: integers N that exactly reproduce their set of digits when we form the set of sums of pairs of adjacent digits.at n=45A296521
• Numbers k for which rank of the elliptic curve y^2=x^3-k*x is 4.at n=12A309034
• Odd composite numbers k such that Sum_{i=1..k-1} 2^i * i^(k-2) == Sum_{i=1..(k-1)/2} i^(k-2) (mod k).at n=21A373734