19821

Appears in sequences

• Expansion of 1/((1-x)(1-4x)(1-5x)(1-8x)).at n=4A021764
• Rotating digits of a(n)^2 right once still yields a square.at n=17A045877
• Expansion of 1/sqrt((1-x)^2-8x^3).at n=12A098480
• a(n) = 4*a(n-1) + 9*a(n-2), for n>1, with a(0)=1, a(1)=3.at n=6A122120
• "Early bird" squares: write the square numbers in a string 149162536496481100... . Sequence gives numbers k such that k^2 occurs in the string ahead of its natural place.at n=36A181585
• Number of nXnXn 0..6 triangular arrays with each element x equal to the number its neighbors equal to 6,0,0,0,0,0,1 for x=0,1,2,3,4,5,6.at n=4A203201
• a(n) = 1+Sum_{k=1..2^n-1} A000010(k).at n=8A255541