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A033157 Begins with (1, 4); avoids 3-term arithmetic progressions. 7
1, 4, 5, 8, 10, 13, 14, 17, 28, 31, 32, 35, 37, 40, 41, 44, 82, 85, 86, 89, 91, 94, 95, 98, 109, 112, 113, 116, 118, 121, 122, 125, 244, 247, 248, 251, 253, 256, 257, 260, 271, 274, 275, 278, 280, 283, 284, 287, 325, 328, 329, 332, 334, 337, 338, 341, 352, 355, 356, 359, 361 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

REFERENCES

Iacobescu, F. 'Smarandache Partition Type and Other Sequences.' Bull. Pure Appl. Sci. 16E, 237-240, 1997.

H. Ibstedt, A Few Smarandache Sequences, Smarandache Notions Journal, Vol. 8, No. 1-2-3, 1997, 170-183.

LINKS

M. L. Perez et al., eds., Smarandache Notions Journal

Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics.

FORMULA

Partial sums of Da(n), where Da(n) is defined in the PARI program.

a(n) = A004793(n) + [n is even] + [ceiling(n/2) is even]. Proof by Lawrence Sze. - Ralf Stephan, Nov 15 2004

PROG

(PARI) Da(n)=if(n<1, 1, if(n%2==0, 3*Da(n/2)+5-13*((n/2)%2)-6*((n/2)%4==2), 3)) (from R. Stephan)

CROSSREFS

See A004793 for a similar case.

Cf. A092482.

Row 2 of array in A093682.

Sequence in context: A162902 A026491 A174396 * A059659 A140459 A139132

Adjacent sequences:  A033154 A033155 A033156 * A033158 A033159 A033160

KEYWORD

nonn

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com).

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Last modified February 17 13:18 EST 2012. Contains 206031 sequences.