cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A255735 Integers that are Rhonda numbers to base 18.

Original entry on oeis.org

1470, 3000, 8918, 17025, 19402, 20650, 21120, 22156, 26522, 36549, 38354, 43281, 46035, 48768, 54229, 54528, 56584, 58216, 58224, 62238, 68096, 68150, 73161, 74024, 74636, 87978, 94041, 114000, 124656, 132240, 133926, 135876, 153105, 153870, 156621, 159819
Offset: 1

Views

Author

Reinhard Zumkeller, Mar 05 2015

Keywords

Comments

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

Examples

			a(1) = 1470 = 4*18^2 + 9*18^1 + 12*18^0 = 2*3*5*7*7,
with 4 * 9 * 12 = 18 * (2+3+5+7+7) = 432;
a(10) = 36549 = 6*18^3 + 4*18^2 + 14*18^1 + 9*18^0 = 3*3*31*131,
with 6 * 4 * 14 * 9 = 18 * (3+3+31+131) = 3024.
		

Crossrefs

Cf. Rhonda numbers to other bases: A100968 (base 4), A100969 (base 6), A100970 (base 8), A100973 (base 9), A099542 (base 10), A100971 (base 12), A100972 (base 14), A100974 (base 15), A100975 (base 16), A255732 (base 20), A255736 (base 30), A255731 (base 60), A255872.
Column k=10 of A291925.

Programs

  • Haskell
    a255735 n = a255735_list !! (n-1)
    a255735_list = filter (rhonda 18) $ iterate z 1 where
       z x = 1 + if r < 17 then x else 18 * z x' where (x', r) = divMod x 18
    -- Function rhonda as in A099542.

A255736 Integers that are Rhonda numbers to base 30.

Original entry on oeis.org

3024, 3168, 5115, 5346, 5950, 6762, 7750, 7956, 8470, 9476, 9576, 9849, 10360, 11495, 13035, 13356, 16335, 22610, 22784, 23864, 37515, 38025, 40704, 40986, 49887, 52925, 59800, 60955, 61812, 67782, 68590, 74800, 78430, 85063, 90160, 90649, 90897, 91540
Offset: 1

Views

Author

Reinhard Zumkeller, Mar 05 2015

Keywords

Comments

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

Examples

			a(1) = 3024 = 3 * 30^2 + 10 * 30^1 + 24 * 30^0 = 2*2*2*2*3*3*3*7,
with 3 * 10 * 24 = 30 * (2+2+2+2+3+3+3+7) = 720;
a(10) = 9476 = 10 * 30^2 + 15 * 30^1 + 26 * 30^0 = 2*2*23*103,
with 10 * 15 * 26 = 30 * (2+2+23+103) = 3900.
		

Crossrefs

Cf. Rhonda numbers to other bases: A100968 (base 4), A100969 (base 6), A100970 (base 8), A100973 (base 9), A099542 (base 10), A100971 (base 12), A100972 (base 14), A100974 (base 15), A100975 (base 16), A255735 (base 18), A255732 (base 20), A255731 (base 60), see also A255872.
Column k=19 of A291925.

Programs

  • Haskell
    a255736 n = a255736_list !! (n-1)
    a255736_list = filter (rhonda 30) $ iterate z 1 where
       z x = 1 + if r < 29 then x else 30 * z x' where (x', r) = divMod x 30
    -- Function rhonda as in A099542.

A255731 Rhonda numbers in sexagesimal number system.

Original entry on oeis.org

3348, 3510, 6750, 17430, 18750, 18876, 18944, 19475, 20564, 21312, 26550, 28280, 37230, 38396, 43940, 48042, 77770, 88270, 91224, 97470, 108882, 111403, 120046, 123630, 181996, 182646, 235467, 253460, 260429, 264735, 278675, 289161, 295960, 296055, 306642
Offset: 1

Views

Author

Reinhard Zumkeller, Mar 05 2015

Keywords

Comments

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

Examples

			a(1) = 3348 = 55 * 60^1 + 48 * 60^0 = 2*2*3*3*3*31,
with 55 * 48 = 60 * (2+2+3+3+3+31) = 2640;
a(10) = 21312 = 5*60^2 + 55*60^1 + 12*60^0 = 2*2*2*2*2*2*3*3*37,
with 5 * 55 * 12 = 60 * (2+2+2+2+2+2+3+3+37) = 3300.
		

Crossrefs

Cf. Rhonda numbers to other bases: A100968 (base 4), A100969 (base 6), A100970 (base 8), A100973 (base 9), A099542 (base 10), A100971 (base 12), A100972 (base 14), A100974 (base 15), A100975 (base 16), A255735 (base 18), A255732 (base 20), A255736 (base 30).
Column k=42 of A291925.

Programs

  • Haskell
    a255731 n = a255731_list !! (n-1)
    a255731_list = filter (rhonda 60) $ iterate z 1 where
       z x = 1 + if r < 59 then x else 60 * z x' where (x', r) = divMod x 60
    -- Function rhonda as in A099542.

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

Original entry on oeis.org

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

Views

Author

Reinhard Zumkeller, Mar 08 2015

Keywords

Comments

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

Examples

			.   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
		

Crossrefs

Programs

  • 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
Previous Showing 11-14 of 14 results.