A255872 Smallest Rhonda number to base b = n-th composite number, cf. A002808.

10206, 855, 1836, 15540, 1568, 560, 11475, 2392, 1000, 1470, 1815, 1632, 2695, 2080, 6764, 7788, 4797, 3094, 3024, 1944, 756, 5661, 8232, 1000, 12296, 5824, 4624, 4851, 8262, 6561, 16583, 14616, 6545, 7225, 11310, 18382, 1995, 16896, 2940, 23465, 8464, 3348

Offset

1,1

Comments

See A099542 for definition of Rhonda numbers and for more links.

Links

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

Eric Weisstein's World of Mathematics, Rhonda Number

Example

.   n |  b |  a(n)              |  a(n) in base b | factorization
. ----+----+--------------------+-----------------+--------------
.   1 |  4 | 10206 = A100968(1) | [2,1,3,3,1,3,2] | 2*3^6*7
.   2 |  6 |   855 = A100969(1) |       [3,5,4,3] | 3^2*5*19
.   3 |  8 |  1836 = A100970(1) |       [3,4,5,4] | 2^2*3^3*17
.   4 |  9 | 15540 = A100973(1) |     [2,3,2,7,6] | 2^2*3*5*7*37
.   5 | 10 |  1568 = A099542(1) |       [1,5,6,8] | 2^5*7^2
.   6 | 12 |   560 = A100971(1) |        [3,10,8] | 2^4*5*7
.   7 | 14 | 11475 = A100972(1) |       [4,2,7,9] | 3^3*5^2*17
.   8 | 15 |  2392 = A100974(1) |        [10,9,7] | 2^3*13*23
.   9 | 16 |  1000 = A100975(1) |        [3,14,8] | 2^3*5^3
.  10 | 18 |  1470 = A255735(1) |        [4,9,12] | 2*3*5*7^2
.  11 | 20 |  1815 = A255732(1) |       [4,10,15] | 3*5*11^2
.  12 | 21 |  1632              |       [3,14,15] | 2^5*3*17
.  13 | 22 |  2695              |       [5,12,11] | 5*7^2*11
.  14 | 24 |  2080              |       [3,14,16] | 2^5*5*13
.  15 | 25 |  6764              |      [10,20,14] | 2^2*19*89
.  16 | 26 |  7788              |      [11,13,14] | 2^2*3*11*59
.  17 | 27 |  4797              |       [6,15,18] | 3^2*13*41
.  18 | 28 |  3094              |       [3,26,14] | 2*7*13*17
.  19 | 30 |  3024 = A255736(1) |       [3,10,24] | 2^4*3^3*7
.  20 | 32 |  1944              |       [1,28,24] | 2^3*3^5

Prog

(Haskell)
a255872 n = head $ filter (rhonda b) $ iterate zeroless 1 where
            -- function rhonda as defined in A099542
            zeroless x = 1 + if r < b - 1 then x else b * zeroless x'
                         where (x', r) = divMod x b
            b = a002808 n

Crossrefs

Cf. A002808, A100968, A100969, A100970, A100973, A099542, A100971, A100972, A100974, A100975, A255735, A255732, A255736.

Cf. A255880.

Row n=1 of A291925.

Sequence in context: A105582 A243819 A258890 * A291925 A255880 A100968

Adjacent sequences: A255869 A255870 A255871 * A255873 A255874 A255875

Keyword

nonn,base

Author

Reinhard Zumkeller, Mar 08 2015

Status

approved