A283565 Numbers n such that n = Sum_{k=1..m} (n mod k) for some m.
0, 1, 2, 7, 8, 9, 10, 13, 15, 19, 22, 23, 25, 31, 37, 49, 51, 52, 57, 72, 95, 98, 100, 133, 140, 146, 152, 158, 168, 189, 196, 212, 315, 348, 376, 383, 396, 407, 416, 451, 452, 497, 521, 541, 548, 551, 568, 583, 586, 592, 593, 657, 663, 683, 729, 780, 784, 794
Offset: 1
Keywords
Examples
(7 mod 1) + (7 mod 2) + (7 mod 3) + (7 mod 4) + (7 mod 5) = 0 + 1 + 1 + 3 + 2 = 7, hence 7 appears in this sequence. (4 mod 1) + (4 mod 2) + (4 mod 3) + (4 mod 4) = 0 + 0 + 1 + 0 = 1, and (4 mod 1) + (4 mod 2) + (4 mod 3) + (4 mod 4) + (4 mod 5) = 0 + 0 + 1 + 0 + 4 = 5, hence 4 does not appear in this sequence.
Links
- Rémy Sigrist, Table of n, a(n) for n = 1..10000
Programs
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PARI
isok(n) = my (s=0); my (k=1); while (s
Comments