login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A101039 Pythagorean years: a Pythagorean year is one whose digits partition into two disjoint sets such that, considering digital sums, the Pythagorean relation 5^2=4^2 + 3^2 is evinced. 0
799, 889, 898, 979, 988, 997, 1699, 1789, 1798, 1879, 1888, 1897, 1969, 1978, 1987, 1996, 2599, 2689, 2698, 2779, 2788, 2797, 2869, 2887, 2896, 2959, 2968, 2977, 2986, 2995, 3499, 3589, 3598, 3679, 3688, 3697, 3769, 3796, 3859, 3886, 3895, 3949, 3958 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

REFERENCES

J. P. Boudine, La geometrie de la chambre a air, pp. 88-90 Vuibert Paris 1998.

LINKS

Table of n, a(n) for n=1..43.

EXAMPLE

1699 and 1888, for instance, are in the sequence (as are all permutations of them) because we have 1+6+9+9=(1+6+9)+9 and (1+8)+(8+8)=1+8+8+8.

All ordered solutions for years through 9999 follow with corresponding additional permutations:

0799 -> {979,997,7099,7909,7990,9079,9097,9709,9790,9907,9970}

0889 -> {898,988,8089,8098,8809,8890,8908,8980,9088,9808,9880}

1699 -> {1969,1996,6199,6919,6991,9169,9196,9619,9691,9916,9961}

1789 -> {1798,1879,1897,1978,1987,7189,7198,7819,7891,7918,7981,...}

1888 -> {8188,8818,8881}

2599 -> {2959,2995,5299,5929,5992,9259,9295,9529,9592,9925,9952}

2689 -> {2698,2869,2896,2968,2986,6289,6298,6829,6892,6928,6982,...}

2779 -> {2797,2977,7279,7297,7729,7792,7927,7972,9277,9727,9772}

2788 -> {2878,2887,7288,7828,7882,8278,8287,8728,8782,8827,8872}

3499 -> {3949,3994,4399,4939,4993,9349,9394,9439,9493,9934,9943}

3589 -> {3598,3859,3895,3958,3985,5389,5398,5839,5893,5938,5983,...}

3679 -> {3697,3769,3796,3967,3976,6379,6397,6739,6793,6937,6973,...}

3688 -> {3868,3886,6388,6838,6883,8368,8386,8638,8683,8836,8863}

4489 -> {4498,4849,4894,4948,4984,8449,8494,8944,9448,9484,9844}

4579 -> {4597,4759,4795,4957,4975,5479,5497,5749,5794,5947,5974,...}

4588 -> {4858,4885,5488,5848,5884,8458,8485,8548,8584,8845,8854}

4669 -> {4696,4966,6469,6496,6649,6694,6946,6964,9466,9646,9664}

5569 -> {5596,5659,5695,5956,5965,6559,6595,6955,9556,9565,9655}

CROSSREFS

Sequence in context: A256026 A200201 A045261 * A121642 A035886 A283899

Adjacent sequences:  A101036 A101037 A101038 * A101040 A101041 A101042

KEYWORD

nonn,base

AUTHOR

Lekraj Beedassy, Jan 21 2005

EXTENSIONS

Extended by Ray Chandler, Jan 25 2005

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 7 15:24 EST 2021. Contains 349581 sequences. (Running on oeis4.)