A185729 - OEIS

A185729

Numbers that are the sum of their first k non-divisors for some k.

5, 8, 12, 51, 56, 85, 87, 105, 132, 164, 224, 249, 280, 321, 324, 343, 357, 363, 366, 405, 427, 428, 553, 583, 591, 618, 638, 654, 689, 699, 820, 918, 978, 1028, 1045, 1077, 1144, 1207, 1261, 1267, 1268, 1342, 1377, 1417, 1477, 1505, 1517, 1691, 1692, 1707, 1758, 1794, 1805, 1883, 1927, 2197, 2322, 2334, 2384, 2461, 2481, 2523, 2525, 2568

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

EXAMPLE

51 is in the sequence because 51 = 2 + 4 + 5 + 6 + 7 + 8 + 9 + 10

(the sum of its first 8 non-divisors)

MATHEMATICA

Select[Range[2600], MemberQ[Accumulate[Complement[Range[#], Divisors[#]]], #]&] (* Harvey P. Dale, Feb 16 2011 *)

PROG

(PARI) is(n)=my(s, t=1); while(s<n, if(n%t++, s+=t)); s==n \\ Charles R Greathouse IV, Nov 23 2015