

A007604


a(n)=a(n1)+a(n1 number of odd terms so far).
(Formerly M0567)


6



1, 2, 3, 4, 6, 9, 12, 16, 22, 31, 40, 52, 68, 90, 121, 152, 192, 244, 312, 402, 523, 644, 796, 988, 1232, 1544, 1946, 2469, 2992, 3636, 4432, 5420, 6652, 8196, 10142, 12611, 15080, 18072, 21708, 26140, 31560, 38212, 46408, 56550, 69161, 81772, 96852
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OFFSET

1,2


COMMENTS

A003056(n) gives the number of odd terms in the first n terms of this sequence. Modulo 2, this sequence becomes A023531.  T. D. Noe, Jul 24 2007
The present definition was the original definition of this sequence. It was later changed to "Sequence formed from rows of triangle A046936", but this seems less satisfactory.  N. J. A. Sloane, Oct 26 2014


REFERENCES

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).


LINKS

T. D. Noe, Table of n, a(n) for n=1..1000


MATHEMATICA

a[n_Integer] := a[n] = Block[{c, k}, c = 0; k = 1; While[k < n, If[ OddQ[ a[k] ], c++ ]; k++ ]; Return[a[n  1] + a[n  1  c] ] ]; a[1] = 1; a[2] = 2; Table[ a[n], {n, 0, 60} ]


PROG

(Haskell)
a007604 n = a007604_list !! (n1)
a007604_list = concat $ map tail $ tail a046936_tabl
 Reinhard Zumkeller, Jan 01 2014


CROSSREFS

Cf. A006336, A046936, A003056.
Sequence in context: A083365 A001935 A286141 * A013950 A018550 A248475
Adjacent sequences: A007601 A007602 A007603 * A007605 A007606 A007607


KEYWORD

nonn,nice,easy


AUTHOR

N. J. A. Sloane, Robert G. Wilson v


EXTENSIONS

Entry revised by N. J. A. Sloane, Oct 26 2014


STATUS

approved



