66666667

Properties

Appears in sequences

• Primes that contain digits 6 and 7 only.at n=24A020469
• Primes that when squared gives numbers with digits in nondecreasing order.at n=24A028865
• Smallest n-digit prime containing only the digits 6 and 7, or 0 if no such prime exists.at n=7A036948
• Smallest prime containing exactly n 6's.at n=7A037065
• Find smallest pair (x,y) such that x^2-y^2 = 11...1 (n times) = (10^n-1)/9; sequence gives value of y.at n=23A048612
• Numbers k such that k^2 contains only digits {4,8,9}.at n=17A053966
• Smallest prime beginning with exactly n 6's.at n=7A065589
• Number of Fibonacci numbers A000045(k), k <= 10^n, which end in 4.at n=9A067275
• Duplicate of A067275.at n=9A073552
• Numbers k with the property that k divides one of the concatenations (k-1)(k-2) or (k-2)(k-1).at n=34A077292
• Numbers n > 2 such that n divides the concatenation of n-2 and n-1.at n=9A088797
• Primes of the form identical digits followed by a 7.at n=21A090147
• Primes of the form 60*R_k + 7, where R_k is the repunit (A002275) of length k.at n=3A093170
• Primes of the form 1 + repdigit. Primes whose totient is a repdigit.at n=9A096505
• a(n) is the least prime following A002280[n] repdigits.at n=8A099660
• Near-repdigit primes with at least two 6's as the repeated digit.at n=3A105978
• Primes such that the outer 2 digits are n and n+1 and all inner digits are 6, where 0 < n < 9.at n=7A108823
• Numbers k such that the k-th triangular number contains only digits {2,7,8}.at n=24A119179
• Numbers k such that k and k^2 use only the digits 4, 6, 7, 8 and 9.at n=35A137145
• Primes of the form 2(10^n-1)/3 * 10^ceiling(log_10(n+1)) + n.at n=1A176272