42024

Appears in sequences

• n written in fractional base 6/4.at n=34A024637
• Palindromes of form k*(k+2); or palindromes 1 less than a square.at n=10A028504
• Palindromes which are the sum of a twin prime pair.at n=4A037076
• Palindromes with exactly 6 prime factors (counted with multiplicity).at n=18A046332
• Obtain m by omitting trailing zeros from n; a(n) = smallest multiple k*m which is a palindrome with even digits, or -1 if no such multiple exists.at n=51A061915
• Smallest multiple k*n of n which has even digits and is a palindrome or becomes a palindrome when 0's are added on the left (e.g., 10 becomes 010, which is a palindrome).at n=51A062293
• Both n and its reverse are one less than a square.at n=10A066619
• Triangle read by rows of numbers of paths in a lattice satisfying certain conditions.at n=41A071949
• Palindromes whose sum of anti-divisors is palindromic.at n=15A073956
• Numbers k such that 10^k + 2*R_k + 7 is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=10A102931
• A convolution triangle of numbers based on A027307.at n=39A110682
• Palindromes that are sandwiched between a prime and a powerful(1) number, in any order.at n=5A113840
• Palindromes which are sums of two consecutive primes.at n=25A162571
• Record numbers of A171063 nonzero period n solutions of x(i)=(x(i-1)+x(i-2)) mod m, as encountered in (n=1,m=1; n=1,m=2; n=2,m=1) antidiagonal order.at n=24A171061
• Record numbers of A171063 nonzero period n solutions of x(i)=(x(i-1)+x(i-2)) mod m, as encountered in (n=1,m=1; n=2,m=1; n=1,m=2) antidiagonal order.at n=25A171062
• Numbers n such that n and n^4 are sums of two twin primes.at n=7A212430
• Start with 0. Successive digits in the sequence must differ by 2. Adjoin the smallest number not yet in the sequence.at n=46A228327
• Number of length n words on {1,2,3} with no more than one consecutive 1 and no more than two consecutive 2's and no more than three consecutive 3's.at n=11A242452
• Triangle, read by rows, T(n,k)=k/n*Sum_{i=0..n-k} C(2*n,n-k-i)*C(2*n+i-1,i).at n=22A257532
• Both k and its reverse are one less than a square.at n=15A287389