1040400

Appears in sequences

• Squares whose digits are squares.at n=33A019544
• Squares such that each digit is a square and the sum of the digits is a square.at n=19A061270
• a(n) = A041041(n-1)^2, n >= 1.at n=4A099374
• Non-palindromic squares whose digit reversal gives a square (possibly with fewer digits).at n=38A161902
• Number of (n+4)X5 binary arrays with every 5X5 subblock commuting with each horizontal and vertical neighbor 5X5 subblock.at n=9A186601
• Numbers n such that phi(sigma(k))/sigma(phi(k)) < phi(sigma(n))/sigma(phi(n)) for all k < n and n is the smallest positive integer with this property.at n=8A227927
• Areas of primitive Heronian triangles K which are perfect squares.at n=24A248108
• Number of (n+2) X (7+2) 0..1 arrays with no 3 X 3 subblock diagonal sum less than the antidiagonal sum or central row sum less than the central column sum.at n=27A258893
• Perfect powers k (exponent greater than 1) such that k-1 and k+1 are both semiprime.at n=16A276564
• Numbers k such that sigma(k) - 3k is prime.at n=14A306492
• Perfect squares of the form a + b^2 + c^3, where a,b,c are consecutive numbers.at n=9A325173
• Numbers k such that (65*k)^2 can be represented in exactly 4 ways as the sum of a positive square and a positive fourth power.at n=20A346594
• Primitives exponential abundant numbers that are not primitives exponential unitary abundant.at n=8A391086
• Primitive exponential Zumkeller numbers that are not primitive exponential unitary Zumkeller numbers.at n=9A391091