121112

Appears in sequences

• Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 87.at n=3A031765
• Array in which the n-th row contains the multiples of n using nonzero digits and having a digit sum of n. Sequence contains the rows and a zero entry for rows with no terms (e.g. 10).at n=41A077755
• Largest k such that round(1/(sqrt(prime(k+1))-sqrt(prime(k)))) = n where prime(n) denotes the n-th prime (conjectured values).at n=26A078693
• Number of fib001 primes (A095086) in range ]2^n,2^(n+1)].at n=22A095066
• Sorted list of strings that can be obtained by starting with 12 and repeatedly doubling any substring in place.at n=23A130838
• Composite numbers whose product of digits is 4.at n=37A201016
• Triangle read by rows in which row n lists the binary words of length n over the alphabet {1,2} with no initial repeats.at n=27A211029
• Good's example of a "Standard List" of prime words over the alphabet {1,2}.at n=16A212659
• Minimal representation (considered minimal in any canonical base b >= 3) of n in a binary system using two distinct digits "1" and "2", not allowing zeros, where a digit d in position p (p = 1,2,3,...,n) represents the value d^p.at n=37A235860
• Positive numbers n such that (digitsum(n))^2 equals (product of digits(n))^3.at n=12A261778
• List of words of length n over an alphabet of size 9 that are in standard order and which have the property that every letter that appears in the word is repeated.at n=32A273978
• Consider the Post tag system described in A284116 (but adapted to the alphabet {1,2}) ; sequence lists the words that terminate in the empty word.at n=41A289675
• To concatenate all terms, to concatenate the odd rank terms or to concatenate the even rank terms produces the same result.at n=32A299823
• Underline all even terms; concatenations of underlined terms and of non-underlined terms both equal the concatenation of the entire sequence. This is the lexicographically earliest such sequence without duplicate terms and with an even digit among the first two terms.at n=12A307312
• The Wythoff representation of n: an alternative way of presenting A189921.at n=24A317208
• Partition the decimal expansion of Pi into non-overlapping strings of length 10: 3141592653, 5897932384,..; a(n) is the position of the strings where digits are different from each other.at n=34A329368
• Numbers k such that k and k+1 are both binary Moran numbers (A334344).at n=37A334345