22472

Appears in sequences

• The prime factors of n are also prime factors of the decimal encoding (A067599) of the prime factorization of n.at n=28A067671
• a(1)=1, a(n) is the smallest integer > a(n-1) such that the largest element in the simple continued fraction for S(n)=1/a(1)+1/a(2)+...+1/a(n) equals prime(n).at n=28A070901
• First occurrence of exactly n 0's in the binary expansion of sqrt(2).at n=10A084187
• Sum of the first n twin prime pairs.at n=33A086169
• Cupolar numbers: a(n) = (n+1)*(5*n^2 + 7*n + 3)/3.at n=23A096000
• Numbers k such that sigma(k) - phi(k) is a brilliant number (A078972).at n=15A115917
• Number of isomers of polyhex hydrocarbons with C_(2h) symmetry with eighteen hexagons.at n=9A120371
• Numbers of the form p^2 * q^3, where p,q are distinct primes.at n=35A143610
• Number of disconnected regular simple graphs on n vertices with girth exactly 3.at n=18A210713
• Primitive integer length of the side of an origin-centered square that contains inside its boundary a point with integer coordinates that is an integer distance from three of the four corners.at n=17A215365
• Numbers of the form p^2*q^3 where p, q are (not necessarily distinct) primes.at n=39A216417
• Numbers of the form x^3 + SumOfCubedDigits(x).at n=28A225051
• Number of (n+1)X(2+1) 0..7 arrays with every 2X2 subblock having the sum of the squares of all six edge and diagonal differences equal to 59.at n=2A233854
• Number of (n+1)X(3+1) 0..7 arrays with every 2X2 subblock having the sum of the squares of all six edge and diagonal differences equal to 59.at n=1A233855
• T(n,k)=Number of (n+1)X(k+1) 0..7 arrays with every 2X2 subblock having the sum of the squares of all six edge and diagonal differences equal to 59 (59 maximizes T(1,1)).at n=7A233859
• T(n,k)=Number of (n+1)X(k+1) 0..7 arrays with every 2X2 subblock having the sum of the squares of all six edge and diagonal differences equal to 59 (59 maximizes T(1,1)).at n=8A233859
• Achilles numbers which are coprime to the sum of their divisors.at n=31A248022
• a(n) = sum_{k = 0..n-1} (-1)^k*C(2*n-1,k)*C(n-1,k), n>0.at n=11A252355
• Primitive values n such that the square with opposite corners (0,0) and (n,n) contains a point (x,y) with integer coordinates, with 0 < x,y < n, at an integer distance from three of the four corners.at n=33A260549
• Number of distinct cardinalities of orbits of lattice points under the automorphism group of the n-dimensional integer lattice.at n=40A270950