26400

Appears in sequences

• a(n) = n^2*(n+1)*(n+2)^2/6.at n=10A004256
• a(n) is least k such that k and 6k are anagrams in base n (written in base 10).at n=14A023098
• a(n) = 10*(n+1)*binomial(n+3,5)/3.at n=7A027790
• a(n) = 12*(n+1)*binomial(n+3,9).at n=3A027794
• a(n) = (n-1)*(2*n-1)*(3*n-1).at n=17A033594
• Numbers n such that phi(n) is a proper substring of n.at n=10A066663
• Numbers n such that the digits of n end in phi(n).at n=11A067206
• Numbers n such that sigma(n) = phi(prime(n)+1).at n=25A067625
• Numbers k such that sigma(k) = phi((prime(k)+prime(k+1))/2).at n=11A068365
• Numbers n such that phi((prime(n)+1)/2)=sigma(n).at n=39A068473
• Expansion of e.g.f. x*exp(5*x)*cosh(x).at n=6A082136
• Molien series for symmetrized weight enumerators of self-dual codes over GF(4) + GF(4)u with u^2 = 0.at n=46A092549
• Largest achievable determinant of a 4 X 4 matrix whose elements are the 16 consecutive integers n-15,...,n.at n=5A097696
• Antidiagonal sums of the row-reversed triangle A048998 of Bernoulli polynomial coefficients.at n=7A122596
• Position of first occurrence of n in A121382.at n=39A122829
• Quasi-mirror of A062196 formatted as a triangular array.at n=52A124051
• Irregular square reversible numbers. Numbers which when squared and written backwards give a square again, but don't satisfy reverse(n^2) = reverse(n)^2.at n=26A129914
• a(4n+k) = 4a(4n+k-1)-6a(4n+k-2)+4a(4n+k-3), for k = 0,1,2; 2*a(4n+3) = 7a(4n+2)-8(4n+1)+2a(4n), with a(0) = a(1) = a(2) = 0, a(3) = 1.at n=18A132152
• Numbers k such that k and k^2 use only the digits 0, 2, 4, 6 and 9.at n=22A136905
• Least number k such that sigma_2(k) >= 2^n.at n=29A141847