id:A055131 - OEIS Search Results

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Those composite s for which A055095[s] = 2.

+0
2

15, 39, 51, 87, 111, 123, 159, 183, 219, 267, 291, 303, 327, 339, 411, 447, 471, 519, 543, 579, 591, 687, 699, 723, 771, 807, 831, 843, 879, 939, 951, 1011, 1047, 1059, 1119, 1167, 1191, 1203, 1227, 1263, 1299, 1347, 1371, 1383, 1527, 1563, 1623, 1671 (list; graph; listen)

	OFFSET	`0,1`
	FORMULA	`a(n) = 3((4A005098[n])+1) = 3*A002144[n] ??? (Conjecture, not yet proved)`
	MAPLE	`find_A055095_is_2_composites := proc(upto_n) local j, a; a := []; for j from 1 to upto_n do if(-1 = (j - wt(GrayCode(qrs2bincode((2j)+1))))) then if(not isprime((2j)+1)) then a := [op(a), ((2*j)+1)]; fi; fi; od; RETURN(a); end;`
	CROSSREFS	`Sequence in context: A032654 A154988 A086096 this_sequence A121051 A139042 A020142` `Adjacent sequences: A055128 A055129 A055130 this_sequence A055132 A055133 A055134`
	KEYWORD	`nonn`
	AUTHOR	`Antti Karttunen Apr 04 2000`
	EXTENSIONS	`More terms from James A. Sellers (sellersj(AT)math.psu.edu), Apr 21 2000`

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Last modified December 17 23:40 EST 2009. Contains 171025 sequences.

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