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A053227 First differences of sigma(n) that are negative. 2
1, 4, 2, 6, 14, 13, 19, 10, 12, 29, 2, 26, 40, 15, 6, 53, 4, 48, 52, 6, 6, 24, 67, 21, 44, 48, 40, 30, 106, 43, 76, 30, 72, 121, 44, 88, 65, 42, 116, 12, 90, 122, 40, 24, 154, 15, 115, 112, 18, 30, 54, 170, 64, 134, 96, 28, 2, 36, 227, 18, 68, 184, 79, 120, 176, 132, 148 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

FORMULA

a(n) = A053222(A053226(n))

MAPLE

with(numtheory): seq( `if`((sigma(i) > sigma(i+1)), (sigma(i) - sigma(i+1)), print( )), i=1..200);

CROSSREFS

Cf. A000203, A053222, A053225.

Sequence in context: A136390 A019610 A058613 * A083760 A099507 A019104

Adjacent sequences:  A053224 A053225 A053226 * A053228 A053229 A053230

KEYWORD

nonn

AUTHOR

Asher Auel (asher.auel(AT)reed.edu) Jan 06 2000

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Last modified February 16 15:27 EST 2012. Contains 205930 sequences.