A073886 - OEIS

A073886

Terms which retain their position in A073885, i.e., terms for which A073885(n) = n.

1, 2, 8, 10, 16, 17, 20, 22, 25, 26, 27, 28, 31, 34, 35, 36, 40, 45, 56, 57, 64, 68, 70, 82, 92, 93, 94, 95, 96, 104, 124, 137, 145, 146, 147, 148, 152, 165, 166, 169, 170, 171, 172, 176, 177, 178, 185, 188, 189, 190, 197, 205, 208, 214, 215, 216, 217, 218, 219

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OFFSET

1,2

LINKS

Robert Israel, Table of n, a(n) for n = 1..10000

MAPLE

S:= [$2..300]:

s:= 1: R:= 1:

for i from 2 do

target:= isprime(i);

found:= false;

for j from 1 to nops(S) while not found do

if isprime(s+S[j]) = target then

found:= true;

s:= s+S[j];

if S[j] = i then R:= R, i fi;

S:= subsop(j=NULL, S);

od;

if not found then break fi;

od:

R; # Robert Israel, Oct 07 2024

MATHEMATICA

For[n=1; s={}; sum=0, n<=300, n++, For[v=1, MemberQ[s, v]||Xor[PrimeQ[n], PrimeQ[sum+v]], v++, Null]; sum+=v; AppendTo[s, a[n]=v]]; Select[Range[300], a[ # ]==#&]

CROSSREFS

Cf. A073885.

Sequence in context: A336176 A375709 A329952 * A079930 A047467 A079599

Adjacent sequences: A073883 A073884 A073885 * A073887 A073888 A073889

KEYWORD

nonn

AUTHOR

Amarnath Murthy, Aug 17 2002

EXTENSIONS

Edited by Dean Hickerson, Oct 22 2002

STATUS

approved