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A134715
Odd Bell numbers.
2
1, 1, 5, 15, 203, 877, 21147, 115975, 4213597, 27644437, 1382958545, 10480142147, 682076806159, 5832742205057, 474869816156751, 4506715738447323, 445958869294805289, 4638590332229999353, 545717047936059989389
OFFSET
1,3
COMMENTS
A000110 except A121293. - Vladimir Reshetnikov, Nov 02 2015
LINKS
FORMULA
a(n) = A000110((6*n-7-(-1)^n)/4) = A000110(A032766(n-1)). - Vladimir Reshetnikov, Nov 05 2015
MAPLE
a := n -> combinat:-bell(n-1 + floor((n-1)/2)):
seq(a(n), n=1..18); # Peter Luschny, Nov 03 2015
MATHEMATICA
Table[BellB[(6 n-7-(-1)^n)/4], {n, 1, 20}] (* Vladimir Reshetnikov, Nov 05 2015 *)
PROG
(PARI) a000110(n) = n!*polcoeff(exp(exp(x+x*O(x^n))-1), n);
for(n=0, 30, if(a000110(n)%2 == 1, print1(a000110(n) ", "))) \\ Altug Alkan, Nov 02 2015
CROSSREFS
Sequence in context: A120602 A004130 A088869 * A053918 A053926 A216463
KEYWORD
easy,nonn
AUTHOR
Omar E. Pol, Nov 11 2007
EXTENSIONS
More terms from Omar E. Pol, Dec 10 2008
STATUS
approved