21010

Appears in sequences

• Convolution of A000201 with itself.at n=35A023663
• n written in fractional base 3/2.at n=15A024629
• a(1) = 1; a(n+1) is the smallest number > a(n) which differs from it at every digit.at n=37A068860
• Full Łukasiewicz word for each rooted plane tree (interpretation e in Stanley's exercise 19) encoded by A014486 (or A063171).at n=15A079436
• Binary numbers with 2 replacing 1 in odd positions.at n=26A095914
• Lexicographically earliest increasing sequence with property that in the concatenation of its terms every pair of consecutive digits differs by 1.at n=15A098766
• 5-Smith numbers.at n=6A103126
• Numbers k such that k+1, k+3, k+7 and k+9 are all primes.at n=19A125855
• 3-smooth numbers in ternary representation.at n=24A131096
• a(n) = prime(2^(n + 1)) - prime(2^n).at n=11A135373
• The sequence alternates even and odd integers but also even and odd digits; it is monotonically increasing and a(n) is always the smallest integer fitting the pattern.at n=18A137667
• Integer part of 2^n/log(2^n).at n=17A141602
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, 0, 1), (0, 1, 1), (1, -1, 1), (1, 1, -1), (1, 1, 1)}.at n=7A151017
• Half the number of length n integer sequences with sum zero and sum of squares 4802.at n=3A157581
• Number of n X 2 binary arrays with every one adjacent to another one horizontally or vertically.at n=7A202796
• T(n,k) = Number of n X k binary arrays with every one adjacent to another one horizontally or vertically.at n=37A202802
• T(n,k) = Number of n X k binary arrays with every one adjacent to another one horizontally or vertically.at n=43A202802
• T(n,k)=Unmatched value maps: number of nXk binary arrays indicating the locations of corresponding elements not equal to any horizontal, diagonal or antidiagonal neighbor in a random 0..2 nXk array.at n=43A219002
• Numbers m such that m+1, m+3, m+7, m+9 and m+13 are all primes.at n=6A245304
• Number of ways to move elements of an nXnXn triangular array to themselves or a neighbor, with no 2-cycles and with no more than 7-1 elements moved to themselves.at n=4A271851