100204

Appears in sequences

• Positive numbers k such that k and 4*k are anagrams in base 8 (written in base 8).at n=27A023075
• Total number of n-digit numbers requiring 2 positive biquadrates in their representation as sum of biquadrates.at n=10A186650
• 1/4 the number of n X n 0..3 symmetric matrices with every element equal to two, three or four horizontal and vertical neighbors.at n=6A211092
• Number of integer partitions of 2n with reverse-alternating sum < 0.at n=25A344743
• G.f.: Sum_{k>=0} x^(k^2) * Product_{j=1..k} ((1 + x^j)/(1 - x^j))^2.at n=30A376854