A084112 Nonprimes in A084111.

1, 16, 48, 80, 81, 112, 405, 567, 625, 704, 832, 891, 1053, 1088, 1216, 1377, 1472, 1539, 1856, 1863, 1984, 2368, 2401, 2624, 2752, 3008, 3392, 3776, 3904, 4032, 4288, 4375, 4544, 4672, 5056, 5312, 5696, 6208, 6464, 6592, 6848, 6875, 6976, 7232, 8125

Offset: 1

Author

Reinhard Zumkeller, May 12 2003

Keywords

• nonn

Comments

A084110(a(n)) = a(n) and A010051(a(n)) = 0.

Examples

			All terms < 10000, and their prime factorizations:
.   n |  a(n) |                 .   n |  a(n) |
.  ---+-------+-----------      .  ---+-------+---------------
.   1 |     1 | 1               .  27 |  3392 | 2^6 * 53
.   2 |    16 | 2^4             .  28 |  3776 | 2^6 * 59
.   3 |    48 | 2^4 * 3         .  29 |  3904 | 2^6 * 61
.   4 |    80 | 2^4 * 5         .  30 |  4032 | 2^6 * 3^2 * 7
.   5 |    81 | 3^4             .  31 |  4288 | 2^6 * 67
.   6 |   112 | 2^4 * 7         .  32 |  4375 | 5^4 * 7
.   7 |   405 | 3^4 * 5         .  33 |  4544 | 2^6 * 71
.   8 |   567 | 3^4 * 7         .  34 |  4672 | 2^6 * 73
.   9 |   625 | 5^4             .  35 |  5056 | 2^6 * 79
.  10 |   704 | 2^6 * 11        .  36 |  5312 | 2^6 * 83
.  11 |   832 | 2^6 * 13        .  37 |  5696 | 2^6 * 89
.  12 |   891 | 3^4 * 11        .  38 |  6208 | 2^6 * 97
.  13 |  1053 | 3^4 * 13        .  39 |  6464 | 2^6 * 101
.  14 |  1088 | 2^6 * 17        .  40 |  6592 | 2^6 * 103
.  15 |  1216 | 2^6 * 19        .  41 |  6848 | 2^6 * 107
.  16 |  1377 | 3^4 * 17        .  42 |  6875 | 5^4 * 11
.  17 |  1472 | 2^6 * 23        .  43 |  6976 | 2^6 * 109
.  18 |  1539 | 3^4 * 19        .  44 |  7232 | 2^6 * 113
.  19 |  1856 | 2^6 * 29        .  45 |  8125 | 5^4 * 13
.  20 |  1863 | 3^4 * 23        .  46 |  8128 | 2^6 * 127
.  21 |  1984 | 2^6 * 31        .  47 |  8192 | 2^13
.  22 |  2368 | 2^6 * 37        .  48 |  8384 | 2^6 * 131
.  23 |  2401 | 7^4             .  49 |  8768 | 2^6 * 137
.  24 |  2624 | 2^6 * 41        .  50 |  8896 | 2^6 * 139
.  25 |  2752 | 2^6 * 43        .  51 |  9536 | 2^6 * 149
.  26 |  3008 | 2^6 * 47        .  52 |  9664 | 2^6 * 151 .
		

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A018252, A010051, A084110.

Subsequence of A084111.

Programs

Haskell

a084112 n = a084112_list !! (n-1)
a084112_list = filter ((== 0) . a010051') a084111_list
-- Reinhard Zumkeller, Jul 31 2014

PARI

f(n) = local(d, m); d = divisors(n); m = 1; for (i = 2, length(d), if (m%d[i], m *= d[i], m = m/d[i])); m; count = 0; i = 0; while (count < 70, i++; if (!isprime(i), if (f(i) == i, count++; print(i)))); \\ David Wasserman, Dec 13 2004

Extensions

More terms from David Wasserman, Dec 13 2004