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

1,1

Links

Table of n, a(n) for n=1..21.

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

Crossrefs

Cf. A000918, A002378, A135013.

Sequence in context: A028337 A215293 A264410 * A321571 A092024 A252741

Adjacent sequences: A135011 A135012 A135013 * A135015 A135016 A135017

Keyword

nonn

Author

N. J. A. Sloane, Feb 10 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

Status

approved