login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A030723
Numbers k such that A030717(k) = 1.
9
1, 2, 5, 10, 17, 22, 28, 35, 59, 60, 69, 70, 71, 72, 81, 84, 85, 94, 97, 98, 99, 100, 101, 110, 113, 115, 116, 117, 118, 119, 128, 131, 133, 134, 135, 136, 137, 139, 148, 151, 153, 154, 155, 156, 157, 158, 160, 161, 162, 171, 174
OFFSET
1,2
LINKS
Michael De Vlieger, Plot a(w(j) + k - 1) at (j,k) for j = 1..512 and w the sequence of partial sums of A030719, showing a(m) = 1 in red and a(m) > 1 in light blue.
MATHEMATICA
nn = 102; c[_] = 0; m = k = a[1] = c[1] = 1; {1}~Join~Reap[Do[w = Union@ Array[a, k]; Do[If[Set[a[j + k], c[w[[j]]]] == 1, Sow[j + k]], {j, Length[w]}]; Do[c[a[j + k]]++, {j, Length[w]}]; k += Length[w], {nn}]][[-1, -1]] (* Michael De Vlieger, Nov 15 2022 *)
CROSSREFS
KEYWORD
nonn
STATUS
approved