21066

Appears in sequences

• Numbers k such that 2^k mod k = 2^k mod k^2.at n=34A068535
• Column 3 of triangle A091602.at n=45A091606
• Numbers k that are not powers of 2 such that 2^k mod k = 2^k mod k^2; or A068535 with powers of 2 excluded.at n=19A125773
• Size of the BDD for the hidden weighted bit function, with the variables in their natural ordering.at n=26A136445
• The number of functions on a finite set that are obtainable by a composition power (excluding identity as power).at n=5A163948
• Reversals of tribonacci numbers (sorted).at n=19A215649
• a(n) is the number of digits in the decimal representation of the smallest power of n that contains nine consecutive identical digits.at n=7A217184
• Number of inequivalent (rotationally and reflectively distinct) ways to place n nonattacking empresses on n X n board.at n=9A218244
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 525", based on the 5-celled von Neumann neighborhood.at n=27A272740
• Number of n-gonal inositol homologs with 2 kinds of achiral proligands.at n=11A283848
• Even bisection of A283848.at n=5A284711
• Number of nX3 0..1 arrays with every element unequal to 0, 1, 2, 6, 7 or 8 king-move adjacent elements, with upper left element zero.at n=14A316688
• Total number of colors used in all colored set partitions of [n] where colors of the elements of subsets are distinct and in increasing order and the colors span an initial interval of the color palette.at n=5A325930
• Numbers k such that the ring of integers of Q(2^(1/k)) is not Z[2^(1/k)].at n=24A342390
• Integers k equal to the sum over A024816(t) mod t, for some steps, starting with t = k and then using the result to feed the next calculation.at n=25A377002