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A130201
Odious oblong (promic) numbers.
2
2, 42, 56, 110, 182, 342, 506, 552, 702, 812, 930, 992, 1190, 1332, 1640, 1722, 2162, 2450, 2756, 2862, 2970, 3080, 3306, 3540, 3782, 4422, 4692, 4970, 5700, 6006, 6320, 6480, 6806, 7310, 7832, 8372, 8742, 9120, 9506, 9900
OFFSET
1,1
LINKS
FORMULA
a(n) = 2*A130202(n). Multiplication by 2 preserves odiousness, hence this sequence is twice odious triangular numbers.
MATHEMATICA
Select[Table[n(n + 1), {n, 100}], OddQ[Plus @@ IntegerDigits[ #, 2]] &]
PROG
(PARI) is(n)=n%2==0 && hammingweight(n)%2 && ispolygonal(n/2, 3) \\ Charles R Greathouse IV, Mar 16 2022
CROSSREFS
Cf. This sequence is the intersection of odious (A000069) and oblong (A002378) numbers.
Sequence in context: A350859 A076391 A348773 * A076392 A291173 A048373
KEYWORD
nonn,easy
AUTHOR
Tanya Khovanova, May 16 2007
EXTENSIONS
Offset corrected by Amiram Eldar, Dec 09 2019
STATUS
approved