login
A222258
Lexicographically earliest injective sequence of nonnegative integers such that the sum of 8 consecutive terms is always divisible by 8.
3
0, 1, 2, 3, 4, 5, 6, 11, 8, 9, 10, 19, 12, 13, 14, 27, 16, 17, 18, 35, 20, 21, 22, 43, 24, 25, 26, 51, 28, 29, 30, 59, 32, 33, 34, 67, 36, 37, 38, 75, 40, 41, 42, 83, 44, 45, 46, 91, 48, 49, 50, 99, 52, 53, 54, 107, 56, 57, 58, 115, 60, 61, 62, 123, 64, 65, 66, 131, 68, 69, 70, 139, 72, 73, 74, 147, 76, 77, 78, 155, 80, 81, 82, 163, 84, 85, 86, 171, 88, 89
OFFSET
0,3
LINKS
E. Angelini, k-chunks sum and division by k, post to the SeqFan list, Mar 22 2013
FORMULA
a(n) = 2 a(n-4) - a(n-8).
G.f.: x*(1 + 2*x + 3*x^2 + 4*x^3 + 3*x^4 + 2*x^5 + 5*x^6)/((1 - x)*(1 + x)*(1 + x^2))^2.
a(n)=n unless n=3 (mod 4) in which case a(n)=2n-3.
PROG
(PARI) A222258(n)=if(n%4==3, n*2-3, n)
CROSSREFS
KEYWORD
nonn
AUTHOR
Eric Angelini and M. F. Hasler, Mar 23 2013
STATUS
approved