A152524 - OEIS

%I #7 Feb 08 2015 04:41:12

%S 508,508,504,504,500,500,496,496,492,492,488,488,484,484,480,480,476,

%T 476,472,472,468,468,464,464,460,460,456,456,452,452,448,448,444,444,

%U 440,440,436,436,432,432,428,428,424,424,420,420,416,416,412,412,408

%N a(n) is the number of L-bit words in which, if up to k bits are perturbed, the resulting change in unsigned L-bit value is n, for L=8 and k=7.

%F a(n) = 511 + (-1)^n - 2*n.

%F G.f.: -4*(-127 + 128*n^2)/((n+1)*(n-1)^2).

%e For n=5, a(5) = 500, i.e., there are 500 possible L-bit words in which up to k bits can be perturbed, leading to a change in the word's unsigned value by 5, for L=8 and k=7.

%e For n=254, a(254) = 4, for L=8 and k=7.

%e For n=255, a(255) = 0, i.e., there is no L-bit word in which up to k bit positions can be perturbed to lead to a change in the unsigned value of the word by 255, for L=8 and k=7.

%K nonn

%O 1,1

%A Phillip Stanley-Marbell (phillip.stanleymarbell(AT)gmail.com), Dec 06 2008, Dec 08 2008