21082

Appears in sequences

• a(n) = Sum_{k=0..n} (k+1) * A026725(n, k).at n=11A027211
• Expansion of Product_{k >= 1} 1/(1-x^k)^c(k), where c(1), c(2), ... = 2 3 2 3 2 3 2 3 ....at n=17A029863
• Number of basis partitions of n+36 with Durfee square size 6.at n=30A053801
• Square root of a(n) contains the n-th Fibonacci number as a string of digits to the immediate right of the decimal point (excluding leading zeros).at n=26A099401
• Numbers that appear exactly five times in A101402. (Also indices of fives in A101403.).at n=14A129117
• Numbers whose square starts with 4 identical digits.at n=21A132391
• Number of line segments connecting exactly 6 points in an n x n grid of points.at n=35A177722
• Number of (n+2) X 5 0..1 arrays with every 3 X 3 subblock having three equal elements in a row horizontally, vertically or nw-to-se diagonally exactly three ways, and new values 0..1 introduced in row major order.at n=16A204376
• Sum of the asymmetry degrees of all compositions of n with parts in {1,2}.at n=19A275439
• Numbers k such that (26*10^k - 413)/9 is prime.at n=18A293593
• Number of sets of exactly ten nonempty words with a total of n letters over n-ary alphabet such that within each prefix of a word every letter of the alphabet is at least as frequent as the subsequent alphabet letter.at n=2A293972
• Number of twice-partitions of n with no repeated partitions.at n=16A296122
• Number of 5Xn 0..1 arrays with every element equal to 0, 2, 4, 5 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.at n=10A303327
• Numbers whose square starts with exactly 4 identical digits.at n=20A346940
• Numbers whose second arithmetic derivative (A068346) is a primorial number (A002110) > 1.at n=31A368702
• Convolution of A000041 and A237271.at n=27A390878