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Intersection of A002378 and A135013.
1

%I #11 Sep 18 2015 03:44:00

%S 2,6,342,8372,15006,32942,45156,170982,369056,3008490,3954132,

%T 644931420,2009953056,12824996256,688604539866900,11580326725041402,

%U 26067179544075560,94815133778597582,502907499251402082,3337168950979864272,7864766939956291580

%N Intersection of A002378 and A135013.

%p A000265 := proc(n) local nshft ; if n mod 2 = 1 then RETURN(n); else nshft := n ; while nshft mod 2 = 0 do nshft := nshft/2 ; od ; RETURN(nshft) ; fi ; end: A135013 := proc(n) option remember ; if n = 1 then RETURN(1) ; else RETURN( A135013(n-1)+A000265(n)) ; fi ; end: isA002378 := proc(n) RETURN( issqr(1+4*n) ) ; end: for n from 1 do a135013 := A135013(n) ; if isA002378(a135013) then printf("%d, ",a135013) ; fi ; od: # _R. J. Mathar_, Feb 11 2008

%Y Cf. A000918, A002378, A135013.

%K nonn

%O 1,1

%A _N. J. A. Sloane_, Feb 10 2008

%E More terms from _R. J. Mathar_, Feb 11 2008

%E a(15)-a(19) from _Donovan Johnson_, Aug 08 2010

%E a(20)-a(21) from _Donovan Johnson_, Jul 24 2011