

A015913


Numbers k such that sigma(k) + 4 = sigma(k+4).


19



3, 7, 13, 19, 37, 43, 67, 79, 97, 103, 109, 127, 163, 193, 223, 229, 277, 307, 313, 349, 379, 397, 439, 457, 463, 487, 499, 613, 643, 673, 739, 757, 769, 823, 853, 859, 877, 883, 907, 937, 967, 1009, 1087, 1093, 1213, 1279, 1297, 1303, 1423
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OFFSET

1,1


COMMENTS

This sequence contains the composite number 305635357, so is different from A023200 and A029710 (305635357 is the only composite member of the present sequence below 10^9).  Jud McCranie, Jan 07 2001


LINKS



MATHEMATICA

Select[Range[1500], DivisorSigma[1, #]+4==DivisorSigma[1, #+4]&] (* Harvey P. Dale, Nov 04 2011 *)


PROG



CROSSREFS



KEYWORD

nonn


AUTHOR



STATUS

approved



