A053225 First differences of sigma(n) that are positive.

2, 1, 3, 6, 7, 5, 16, 10, 7, 21, 22, 4, 36, 11, 16, 42, 31, 6, 43, 22, 34, 54, 40, 76, 36, 26, 66, 48, 10, 108, 34, 8, 23, 60, 58, 48, 123, 40, 10, 16, 72, 106, 5, 140, 24, 60, 144, 56, 16, 132, 73, 61, 114, 106, 172, 106, 96, 126, 66, 216, 53, 56, 156, 127, 76, 204, 44, 36

Offset: 1

Author

Asher Auel, Jan 06 2000

Keywords

• nonn

Crossrefs

Cf. A000203, A053222, A053227.

Programs

Maple

with (numtheory): seq( `if`((sigma(i) < sigma(i+1)),(sigma(i+1)-sigma(i)),print( )), i=1..139);

Formula

a(n) = A053222(A053224(n))