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A268292
a(n) is the total number of isolated 1's at the boundary between n-th and (n-1)-th iterations in the pattern of A267489.
2
0, 0, 0, 0, 0, 0, 0, 1, 3, 5, 7, 9, 11, 14, 18, 22, 26, 30, 34, 39, 45, 51, 57, 63, 69, 76, 84, 92, 100, 108, 116, 125, 135, 145, 155, 165, 175, 186, 198, 210, 222, 234, 246, 259, 273, 287, 301, 315, 329, 344, 360, 376, 392, 408, 424, 441
OFFSET
0,9
COMMENTS
Refer to pattern of A267489, The total number of isolated 1's is a(n) and A112421 when consider at the boundary between n-th and (n-1)-th iterations and at the boundary in the same iterations concatenate on horizontal respectively. See illustrations in the links.
Empirically, a(n+4) gives the number of solutions m where 0 < m < 2^n and A014682^n(m) < 3 and A014682^n(m+2^n) = A014682^n(m)+9. - Thomas Scheuerle, Apr 25 2021
FORMULA
Empirical g.f.: x^7 / ((1-x)^3*(1-x+x^2)*(1+x+x^2)). - Colin Barker, Jan 31 2016
PROG
(PARI) a = 3; d1 = 2; print1("0, 0, 0, 0, 0, 0, 0, 1, 3, ");
for (n = 3, 100, d2 = 0; if (Mod(n, 6)==1 || Mod(n, 6)==2, d2 = 1); d1 = d1 + d2; a = a + d1; print1(a, ", "))
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Kival Ngaokrajang, Jan 31 2016
STATUS
approved