20188

Appears in sequences

• Expansion of e.g.f. arcsin(exp(x)*log(x+1)).at n=7A012275
• Gaps of 2 in sequence A038593 (upper terms).at n=19A038644
• (n+4)^3 - n^3.at n=38A038866
• Non-palindromic number and its reversal are both multiples of 14.at n=38A062913
• Partial sums of A001158: Sum_{j=1..n} sigma_3(j).at n=15A064603
• Sieve performed by successive iterations of steps where step m is: keep m terms, remove the next 2 and repeat; as m = 1,2,3,.. the remaining terms form this sequence.at n=37A112560
• a(n) = 4 + floor((3 + Sum_{j=1..n-1} a(j))/4).at n=38A120163
• a(1)=1, a(n) = a(n-1) + n^5 if n odd, a(n) = a(n-1) + n if n is even.at n=6A140163
• Greatest number m such that the fractional part of (Pi-2)^A153719(m) >= 1-(1/m).at n=13A153723
• Greatest number m such that the fractional part of (Pi-2)^A153720(n) >= 1-(1/m).at n=7A153724
• Number of peaks at odd level in all Dyck paths of semilength n with no UUU's and no DDD's, (U=(1,1), D=(1,-1)). These Dyck paths are counted by the secondary structure numbers (A004148).at n=12A166292
• Number of partitions p of n such that the m(M(p)) is a part, where m = multiplicity, M = the maximum multiplicity of the parts of p.at n=43A240538
• Decimal value a(n) of the binary number b(n) obtained by starting from n, sequentially concatenating all binary numbers down to 1 and then sequentially concatenating all binary numbers from 2 up to n.at n=3A261135
• Number of nX4 0..1 arrays with every element equal to 0, 1, 2, 5 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.at n=6A303178
• T(n,k) = Number of n X k 0..1 arrays with every element equal to 0, 1, 2, 5 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.at n=51A303182
• Number of 7Xn 0..1 arrays with every element equal to 0, 1, 2, 5 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.at n=3A303187
• a(n) appears in the congruences modulo 4 or 32 of Markoff numbers m(n) = A002559(n) for odd or even m(n).at n=38A309376
• a(n) = minimal positive k such that the concatenation of the decimal digits of n,n+1,...,n+k is divisible by n+k+1, or -1 if no such k exists.at n=37A332580
• Numbers k such that k and k + 1 are both lazy-Lucas-Niven numbers (A351719).at n=42A351720