28900

Appears in sequences

• Truncated tetrahedral numbers: a(n) = (1/6)*(n+1)*(23*n^2 + 19*n + 6).at n=19A005906
• a(n) = (5*n)^2.at n=34A016850
• a(n) = (6*n + 2)^2.at n=28A016934
• a(n) = (7*n+2)^2.at n=24A017006
• a(n) = (8*n + 2)^2.at n=21A017090
• a(n) = (9*n + 8)^2.at n=18A017258
• a(n) = (10*n)^2.at n=17A017270
• a(n) = (11*n + 5)^2.at n=15A017450
• a(n) = (12*n + 2)^2.at n=14A017546
• Squares which are a decimal concatenation of two or more squares.at n=40A019547
• Least m such that if r and s in {1/1, 1/4, 1/9,..., 1/n^2} satisfy r < s, then r < k/m < s for some integer k.at n=42A024827
• Numbers k such that k^2 is palindromic in base 13.at n=26A029998
• Squares which are palindromes in base 13.at n=6A029999
• Smallest nontrivial extension of n^2 which is a square.at n=16A030686
• Denominator of 1/25 - 1/n^2.at n=29A061044
• Squares with digital root 1.at n=37A061099
• Numbers k such that phi(2*sigma(k)) = 2*sigma(phi(k)).at n=15A067709
• Smallest integer > 1 which is both n-gonal and centered n-gonal.at n=36A072277
• Numbers k such that sigma(phi(k)) divides phi(sigma(k)).at n=23A073858
• Numbers k not in A065036 but such that tau(k) = omega(k)^3.at n=27A074853