



1, 2, 3, 4, 6, 8, 10, 12, 16, 20, 24, 28, 36, 44, 52, 60, 76, 92, 108, 124, 156, 188, 220, 252, 316, 380, 444, 508, 636, 764, 892, 1020, 1276, 1532, 1788, 2044, 2556, 3068, 3580, 4092, 5116, 6140, 7164, 8188, 10236, 12284, 14332, 16380, 20476, 24572, 28668, 32764
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OFFSET

1,2


COMMENTS

Partial sums of powers of 2 repeated 4 times.
The first few terms of this series appear in the reference by Szymczak, et al., as contour levels in intensity maps of maser emissions.


LINKS

Table of n, a(n) for n=1..52.
Szymczak, M.; Cohen, R. J.; Richards, A. M. S., Full polarization structure of the OH mainline maser envelopes of W Hydrae
Index entries for linear recurrences with constant coefficients, signature (1,0,0,2,2).


FORMULA

G.f.: x*(1+x)*(1+x^2) / ( (x1)*(2*x^41) ).  R. J. Mathar, Nov 21 2011


EXAMPLE

a(5) = 1+1+1+1+2 = 6.


PROG

(BASIC) for i=0 to 12 : for j=1 to 4 : s=s+2^i : print s : next j : next i


CROSSREFS

Cf. A027383, A200672, A200675.
Sequence in context: A067069 A100497 A191283 * A088881 A020697 A175381
Adjacent sequences: A200675 A200676 A200677 * A200679 A200680 A200681


KEYWORD

nonn


AUTHOR

Jeremy Gardiner, Nov 20 2011


STATUS

approved



