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A079717
Subminimal numbers, from minimal numbers by analogy with subfactorials.
0
0, 1, 1, 2, 4, 6, 9, 13, 18, 22, 24, 44, 53, 66, 71, 88, 132, 212, 265, 309, 331, 353, 377, 464, 477, 618, 927, 1059, 1130, 1324, 1507, 1854, 1907, 2318, 2384, 2472, 2781, 3390, 3708, 4521, 5297, 5562, 5651, 7416, 9271, 9535, 10198, 11919, 13562, 16223, 16687, 16952, 17164, 18541, 20395, 22249
OFFSET
1,4
FORMULA
a(n) = floor(A007416(n)/e + 1/2).
EXAMPLE
a(6) = 6 because the 6th minimal number is 16 and floor(16/e + 1/2) = 6.
MATHEMATICA
lim = 10^5; s = DivisorSigma[0, Range@ lim]; t = Select[Most@ Union[First@ FirstPosition[s, #] & /@ Range@ 200], # <= lim &]; Table[Floor[t[[n]]/E + 1/2], {n, 56}] (* Michael De Vlieger, Dec 20 2015, Version 10 *)
PROG
(PARI) is_a007416(n)=my(d=numdiv(n)); for(i=1, n-1, if(numdiv(i)==d, return(0))); 1;
for(n=1, 1e4, if(is_a007416(n), print1(floor(n/exp(1) + 1/2), ", "))); \\ Altug Alkan, Dec 20 2015
CROSSREFS
Sequence in context: A006697 A294860 A183920 * A247179 A319158 A175780
KEYWORD
nonn
AUTHOR
Michael Joseph Halm, Feb 17 2003
EXTENSIONS
More terms from Michael De Vlieger, Dec 20 2015
STATUS
approved