A285526 - OEIS

%I #4 Apr 23 2017 01:13:28

%S 4,12,20,27,35,43,51,59,67,74,82,90,98,106,113,121,129,137,145,153,

%T 160,168,176,184,192,200,207,215,223,231,239,246,254,262,270,278,286,

%U 293,301,309,317

%N Terms of A285524 that mark the beginning of four consecutive equal values.

%o (PARI) half(n) = if (n % 2, n\2, n/2 - 1);

%o a285524(n) = {v = vector(half(n), d, d!*(d + 1)!*(2^(n-2*d-1)*stirling(n-d, d+1, 2))); w = vecsort(v,,1); w[#w];}

%o lista(nn) = {v = vector(nn, n, a285524(n+3)); for (k=1, #v-4, if ((v[k] == v[k+1]) && (v[k] == v[k+2]) && (v[k] == v[k+3]), print1(v[k], ", ")););}

%Y Cf. A285524, A285525.

%K nonn,more

%O 1,1

%A _Michel Marcus_, Apr 20 2017