Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A055131
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A055131 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*((4*A005098[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((2*j)+1))))) then if(not isprime((2*j)+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

page 1

Search completed in 0.002 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

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


AT&T Labs Research