22111

Properties

Appears in sequences

• Primes that contain digits 1 and 2 only.at n=9A020450
• Primes in which each digit occurs in runs of at least 2.at n=3A034873
• Primes having only {0, 1, 2} as digits.at n=24A036953
• Numbers k such that the digits of k^3 occur with the same frequency.at n=56A052047
• Numbers k such that k^3 is a cube whose digits occur with an equal minimum frequency of 2.at n=15A052051
• Number of step shifted (decimated) sequence structures using exactly two different symbols.at n=17A056396
• Numbers in Morse code, with 1 for a dot, 2 for a dash and 0 between digits/letters.at n=7A060109
• A064637 converted to factorial base.at n=23A064477
• Decimal encoding of the prime factorization of n: concatenation of prime factors and exponents.at n=42A067599
• a(1) = 11 by convention; for n > 1, if n = p^a*q^b... then a(n) = concatenate(p,a,q,b,...).at n=43A068633
• Digitized partition numbers: numbers with (weakly) decreasing digits ordered by sum of their digits then by the numbers themselves.at n=41A068743
• a(1) = 1; a(2n) is smallest prime starting with a(2n-1) and a number with no insignificant zeros, and a(2n+1) is smallest prime ending in a(2n-1). Alternate left and right concatenation yielding primes.at n=4A069613
• a(1) = 1; a(2n) = smallest prime starting (most significant digits) with a(2n-1). a(2n+1) = smallest prime ending (least significant digits) in a(2n).at n=4A069628
• The zero-free, right-to-left factorial walk encoding for each rooted plane tree encoded by A014486. Sequence A071155 shown with factorial expansion (A007623).at n=26A071157
• Left-to-right binary enumeration.at n=33A081242
• Prime numbers such that first reversing digits and after squaring equals the result of first-squaring and after-reversing. Primes in A085305.at n=35A085306
• Fibonacci sequence in base 2 of the alternate number system.at n=9A085652
• Primes whose decimal representation also represents a prime in base 3.at n=10A089981
• Primes of the form 5k^2 + 5k + 1.at n=34A090562
• Primes whose decimal representation is a valid number in base 5 and interpreted as such is again a prime.at n=36A090708