23944

Appears in sequences

• 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=39A112560
• Expansion of q / (chi(-q) * chi(-q^3) * chi(-q^5) * chi(-q^15)) in powers of q where chi() is a Ramanujan theta function.at n=45A123632
• Convolution square of A003106.at n=45A145468
• A functionally symmetric Polynomial as a triangle of coefficients: p(x,n)=If[n == 0, 1, (x + 1)^n + 2^(n - 3)*Sum[(3^(m-1) + 2*m+1 )*x^m*(1 + x^(n - 2*m)), {m, 1, n - 1}]].at n=37A146958
• A functionally symmetric Polynomial as a triangle of coefficients: p(x,n)=If[n == 0, 1, (x + 1)^n + 2^(n - 3)*Sum[(3^(m-1) + 2*m+1 )*x^m*(1 + x^(n - 2*m)), {m, 1, n - 1}]].at n=43A146958
• a(n) = 2*n*(7*n + 5).at n=41A195027
• Numbers k such that k^2+1, (k+2)^2+1 and (k+6)^2+1 are prime.at n=37A302021
• Number of 7Xn 0..1 arrays with every element equal to 0, 1, 4 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.at n=7A302520
• a(n) = Sum_{k=0..n} r_4(k^2 + 1), where r_4(k) is the number of ways of writing k as a sum of 4 squares (A000118).at n=18A333174
• a(n) = a(n-2) + 4*a(n-4) - 2*a(n-8) - a(n-10), with a[0..9] = [1, 1, 1, 2, 3, 5, 7, 13, 18, 31].at n=24A365274
• Numbers k such that all primes dividing the k-th composite number divide k as well.at n=37A368309