A135014 Intersection of A002378 and A135013.

2, 6, 342, 8372, 15006, 32942, 45156, 170982, 369056, 3008490, 3954132, 644931420, 2009953056, 12824996256, 688604539866900, 11580326725041402, 26067179544075560, 94815133778597582, 502907499251402082, 3337168950979864272, 7864766939956291580

Offset: 1

Author

N. J. A. Sloane, Feb 10 2008

Keywords

• nonn

Crossrefs

Cf. A000918, A002378, A135013.

Programs

Maple

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

Extensions

More terms from R. J. Mathar, Feb 11 2008

a(15)-a(19) from Donovan Johnson, Aug 08 2010

a(20)-a(21) from Donovan Johnson, Jul 24 2011