A160007 Deficient numbers more than 1 unit away from their predecessors.

7, 13, 19, 21, 25, 29, 31, 37, 41, 43, 49, 55, 57, 61, 67, 71, 73, 79, 81, 85, 89, 91, 97, 101, 103, 105, 109, 113, 115, 121, 127, 133, 139, 141, 145, 151, 157, 161, 163, 169, 175, 177, 181, 187, 193, 197, 199, 201, 205, 209, 211, 217, 221, 223, 225, 229, 235

Offset

1,1

Links

Rainer Rosenthal, Table of n, a(n) for n = 1..2488

Example

The first dozen deficient numbers are 1,2,3,4,5,7,8,9,10,11,13,14. There are "jumps" between a(5) and a(6), and between a(10) and a(11), i.e., at 7 and 13.

Prog

(PARI) lista(nn) = {last = 0; for (i = 1, nn, if (sigma(i) < 2*i, if (i > last + 1, print1(i, ", "); ); last = i; ); ); } \\ Michel Marcus, Sep 02 2013

Crossrefs

Cf. A005100 (deficient numbers).

Cf. A353448.

Sequence in context: A304995 A339657 A330946 * A024613 A024606 A074628

Adjacent sequences: A160004 A160005 A160006 * A160008 A160009 A160010

Keyword

nonn

Author

Don Love (moptop35(AT)hotmail.com), Apr 29 2009

Extensions

More terms from Don Love (moptop35(AT)hotmail.com), May 01 2009

Status

approved