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A053239
First differences between n for which sigma(n) > sigma(n+1), which are not 2.
7
4, 1, 1, 4, 4, 1, 1, 1, 1, 4, 4, 1, 1, 4, 4, 1, 1, 4, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 4, 3, 1, 4, 1, 1, 4, 4, 1, 1, 3, 1, 4, 1, 1, 4, 1, 1, 4, 1, 1, 4, 4, 4, 3, 1, 1, 1, 4, 4, 3, 1, 1, 1, 4, 4, 1, 1, 1, 1, 4, 1, 1, 1, 1, 4, 3, 1, 4, 4, 1, 1, 4, 4, 1, 1, 3, 1, 3, 1, 1, 1, 1, 1, 4, 4, 1, 1, 4, 1, 1, 4, 4, 3, 1, 3, 1
OFFSET
1,1
FORMULA
The expansion of A053238 excluding 2's. a(n) = A053238(A053240(n)).
MAPLE
with(numtheory): f := [seq( `if`((sigma(i) > sigma(i+1)), i, print( )), i=1..5000)];
seq( `if`(f[i+1] - f[i] <> 2, f[i+1] - f[i], print( )), i=1..2000);
KEYWORD
nonn
AUTHOR
Asher Auel, Jan 10 2000
STATUS
approved