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

A100987 Integers that are Rhonda numbers to some base.

Original entry on oeis.org

560, 756, 800, 855, 1000, 1029, 1134, 1470, 1568, 1632, 1750, 1815, 1836, 1944, 1995, 2080, 2100, 2392, 2472, 2662, 2695, 2709, 2835, 2940, 3000, 3024, 3060, 3087, 3094, 3168, 3240, 3264, 3348, 3456, 3510, 3600, 3672, 3675, 3744, 3750, 3813, 3888, 3952, 3976
Offset: 1

Views

Author

Mark Hudson (mrmarkhudson(AT)hotmail.com), Nov 25 2004

Keywords

Comments

See sequence A099542 for definition of Rhonda numbers and for some links.

Examples

			560 is a Rhonda number to base 12. 756 is a Rhonda number to base 33. 800 is a Rhonda number to base 12 etc. No integer smaller than 560 is a Rhonda number and there exists no Rhonda number between 560 and 756.
		

Crossrefs

Cf. A099542 for definition of Rhonda numbers. A100968-A100975 for Rhonda numbers for specific bases.
Cf. A291925.

Extensions

Offset changed to 1 by Alois P. Heinz, Sep 09 2017

A100988 Integers that are Rhonda numbers to more than one base.

Original entry on oeis.org

1000, 2940, 4200, 4212, 4725, 5670, 5824, 5832, 6776, 6864, 7040, 7140, 8296, 9476, 9633, 10200, 11016, 11050, 11160, 11495, 11935, 12393, 12474, 13068, 13260, 13671, 14014, 14322, 14406, 15680, 15750, 15912, 16240, 16821, 17056, 17820, 18270, 18655, 18700
Offset: 1

Views

Author

Mark Hudson (mrmarkhudson(AT)hotmail.com), Nov 25 2004

Keywords

Comments

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

Examples

			1000 is a Rhonda number to bases 16 and 36. 2940 is a Rhonda number to bases 56 and 76. 5670 is a Rhonda number to bases 36, 106, 108 and 196.
		

Crossrefs

Cf. A099542 for definition of Rhonda numbers. A100968 to A100975 for Rhonda numbers to specific bases. A100987 for integers that are Rhonda numbers to some base.
Cf. A291925.

Extensions

New offset and terms a(12)-a(39) from Alois P. Heinz, Sep 09 2017
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