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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. 1
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 (list; graph; refs; listen; history; text; internal format)
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: A140895 A191714 A126150 * A248831 A227729 A096966

Adjacent sequences:  A291053 A291054 A291055 * A291057 A291058 A291059

KEYWORD

nonn

AUTHOR

Robert Israel, Oct 20 2017

STATUS

approved

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Last modified April 11 12:38 EDT 2021. Contains 342886 sequences. (Running on oeis4.)