A236845 - OEIS

A236845

Numbers that occur in more than one way as results of "upward" remultiplication (GF(2)[X] -> N) of some number.

91, 117, 143, 171, 182, 234, 247, 273, 286, 333, 342, 351, 361, 364, 369, 429, 451, 468, 471, 494, 501, 513, 539, 546, 572, 609, 637, 666, 675, 684, 687, 702, 721, 722, 728, 738, 741, 803, 819, 847, 858, 902, 936, 942, 949, 957, 981, 988, 999, 1001, 1002, 1026, 1053, 1078, 1083, 1092, 1107, 1125

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OFFSET

1,1

COMMENTS

Numbers that occur more than once in A234742.

Those terms that encode an irreducible polynomial in ring GF(2)[X] with their binary representation (that is, those that are in A014580) seem to occur also all in A091214 (that is, are a subsequence of the latter).

If n is a term, then 2n is also a term.

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..5636

PROG

(Scheme, with Antti Karttunen's IntSeq-library)

(define A236845 (MATCHING-POS 1 0 (lambda (n) (> (A236853 n) 1))))

CROSSREFS

Positions of terms larger than one in A236853.

Cf. A236844, A091214, A014580.

Cf. also A236835.

Sequence in context: A261260 A161945 A140389 * A157345 A092125 A005935

Adjacent sequences: A236842 A236843 A236844 * A236846 A236847 A236848

KEYWORD

nonn

AUTHOR

Antti Karttunen, Jan 31 2014

STATUS

approved