A104205 If mod[n,4]=0 then a(n)=a(n-1), if mod[n,4]=1 then a(n)=a(n-2)+a(n-3), if mod[n,4]=2 then a(n)=a(n-3)+a(n-4)+a(n-5), if mod[n,4]=2 then a(n)=a(n-4)+a(n-5)+a(n-6)+a[n-7].

0, 1, 1, 2, 3, 5, 8, 4, 4, 12, 17, 20, 20, 37, 49, 53, 53, 102, 139, 159, 159, 298, 400, 453, 453, 853, 1151, 1310, 1310, 2461, 3314, 3767, 3767, 7081, 9542, 10852, 10852, 20394, 27475, 31242, 31242, 58717, 79111, 89963, 89963, 169074, 227791, 259033, 259033

Offset

0,4

Links

Table of n, a(n) for n=0..48.

Mathematica

a[n_Integer?Positive] := If[Mod[n, 4] == 0, a[n] = a[n - 1], If[Mod[n, 4] == 1, a[n] = a[n - 2] + a[n - 3], If[Mod[n, 4] == 1, a[n] = a[n - 3] + a[n - 4] + a[ n - 5], a[n] = a[n - 4] + a[n - 5] + a[n - 6] + a[n - 7]]]] a[0] = 0; a[1] = 1; a[2] = 1; a[3] = 2; a[4] = 3; a[5] = 5; a[6] = 8 aa = Table[a[n], {n, 0, 200}]

Crossrefs

Sequence in context: A105472 A030132 A004090 * A267758 A333301 A166015

Adjacent sequences: A104202 A104203 A104204 * A104206 A104207 A104208

Keyword

nonn

Author

Roger L. Bagula, Mar 13 2005

Status

approved