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%I #18 Jul 17 2020 12:05:32
%S 2,5,8,11,12,14,20,23,26,27,29,35,41,42,44,50,53,56,57,65,68,74,83,86,
%T 87,89,95,98,113,116,117,119,125,128,131,132,134,140,146,147,155,158,
%U 173,176,177,179,191,192,194,200,209,215,221,222,224,230,233,239,245,251,252,254
%N Indices m for which A177961(m) = 2 + m.
%C All m for which 2*m+1 is in A003627 are in the sequence:
%C This concerns m=2, 5, 8, 11, 14, 20, 23, 26, 29, 35,...
%C Union of (A003627-1)/2 and (A132235+1)/2. - _Robert Israel_, Jul 31 2015
%H Robert Israel, <a href="/A177966/b177966.txt">Table of n, a(n) for n = 1..10000</a>
%p A090368 := proc(n) A020639(2*n-1) ; end proc:
%p A177961 := proc(n) (A090368(n)+A090368(n+1)) /2 ; end proc:
%p isA177966 := proc(n) A177961(m) = m+2 ; end proc:
%p for m from 1 to 800 do if isA177966(m) then printf("%d,",m) ; end if; end do:
%p # _R. J. Mathar_, Oct 25 2010
%p N:= 1000: # to get all terms <= N
%p A1:= map(t -> (t-1)/2, select(isprime, {seq(6*i-1, i=1..(N+1)/3)})):
%p A2:= map(t -> (t+1)/2, select(isprime, {seq(23+30*i,i=0..(N-12)/15)})):
%p sort(convert(A1 union A2,list));
%p # _Robert Israel_, Jul 31 2015
%t M = 1000; (* to get all terms <= M *)
%t A1 = (Select[Table[6 i - 1, {i, 1, (M + 1)/3}], PrimeQ] - 1)/2;
%t A2 = (Select[Table[23 + 30 i, {i, 0, (M - 12)/15}], PrimeQ] + 1)/2;
%t Union[A1, A2] (* _Jean-François Alcover_, Jul 17 2020, after _Robert Israel_ *)
%Y Cf. A003627, A132235, A177961, A177964, A177965.
%K nonn
%O 1,1
%A _Vladimir Shevelev_, May 16 2010
%E Corrected (11, 23, 27, etc. inserted) and extended by _R. J. Mathar_, Oct 25 2010
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