31213

Appears in sequences

• n written in fractional base 5/3.at n=38A024633
• Palindromic numbers which are the difference of two positive cubes.at n=6A038808
• Base-10 palindromes that starts with 3.at n=34A043038
• Economical palindromes.at n=4A047739
• Triangle with columns built from certain power sequences.at n=51A067402
• Seventh column of triangle A067402.at n=3A067407
• Numbers k such that the squarefree part of k equals A062799(k).at n=37A069551
• Triangular array T(n,k) (n >= 1, 1 <= k <= n) read by rows, where T(n,k) = smallest number x such that Mod[sigma[x],n]=k.at n=75A074625
• Smallest multiple of n which begins with R(n) and ends in n where R(n) (A004086) is the digit reversal of n. Suitable number of zeros are assumed to the left of the MSD if required.at n=12A077741
• Smallest palindromic multiple of n in which n is a substring (anywhere), or 0 if n = 10k or no such number exists.at n=12A084044
• Numbers of the form (7^i)*(13^j).at n=16A108056
• Numbers n such that n and its digit reversal R(n) both are difference of positive cubes.at n=30A109879
• Composite numbers k that divide 3^k - 2^k - 1, excluding powers of 2, 3 and 7.at n=38A127073
• Biquadrateful (i.e., not biquadrate-free) palindromes.at n=22A133514
• A triangular sequence of coefficients based on a skip prime prime power sequence: t(n,m)=Prime[m + 1]^n*Prime[m + 3]; qualified so the m=0 and n=0 terms are well-defined.at n=13A141500
• Positive numbers y such that y^2 is of the form x^2+(x+16807)^2 with integer x.at n=10A156713
• Palindromes that are the sum of two positive cubes.at n=12A162710
• Triangle read by rows in which row n lists n+1 terms, starting with n^5 and ending with n^6, such that the difference between successive terms is equal to n^5 - n^4.at n=29A163285
• Number of 0..n arrays x(0..4) of 5 elements with each no smaller than the sum of its previous elements modulo (n+1).at n=11A200254
• Palindromic composite numbers starting with a digit 3.at n=22A222726