A291056 a(n) = k if the first appearance of n in A077618 is at index k, or 0 if k does not appear in A077618.

4, 1, 6, 78, 102, 130, 66, 30, 510, 1218, 4002, 4578, 390, 14326, 14430, 858, 690, 330, 1722, 5106, 11310, 1110, 13090, 3666, 46662, 10230, 44574, 210, 9570, 4290, 32010, 29946, 30498, 13398, 9282, 15810, 11730, 25194, 12090, 36890, 103730, 194370, 239190, 86430, 79230, 6006, 359310, 85470, 2730, 211470

Offset

0,1

Comments

Conjecture: all positive integers appear in A077618, so a(n) is never 0.

Links

Robert Israel, Table of n, a(n) for n = 0..168

Example

a(3) = 78 because A077618(78)=3 and this is the first appearance of 3 in A077618.

Maple

N:= 10^6: # to get all terms before the first where a(n) > N
M:= map(numtheory:-bigomega, [$1..N]):
S:= map(numtheory:-issqrfree, [$1..N]):
f:= proc(n) local m, k, t;
  if not S[n] then return 0 fi;
  m:= M[n];
  t:= 1;
  for k from n-1 to 1 by -1 do
    if M[k] = m then
      if S[k] then return t
      else t:= t+1
      fi;
    fi
  od;
  t
end proc;
R:= map(f, [$1..N]):
A:= NULL:
for i from 0 do
   j:= ListTools:-Search(i, R);
   if j = 0 then break fi;
   A:= A, j
od:
A;

Crossrefs

Sequence in context: A374370 A364509 A349545 * A248831 A227729 A096966

Adjacent sequences: A291053 A291054 A291055 * A291057 A291058 A291059

Keyword

nonn

Author

Robert Israel, Oct 20 2017

Status

approved