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.

Showing 1-3 of 3 results.

A086533 Numbers in A014092 splittable into a sum of a single number pair (both distinct from 1) having a product that belongs to A086473.

Original entry on oeis.org

17, 65, 89, 127, 137, 163, 179, 185, 191, 233, 247, 269, 305, 343, 427, 457, 547, 569, 583, 613, 637, 667, 673, 697, 733, 757, 779, 787, 817, 821, 853, 929, 967, 977, 989, 997, 1045, 1087, 1117, 1207, 1267, 1273, 1289, 1297, 1327, 1345, 1357
Offset: 1

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Author

Lekraj Beedassy, Sep 10 2003

Keywords

Comments

The first term is the sum solution of Martin Gardner's "Impossible Problem" for numbers each with an upper bound anywhere between 62 and 100.

References

  • M. Gardner,"Mathematical Games" Problem 1 pp. 20, 23-24 in Scientific American, Dec. 1979.

Links

Crossrefs

For the corresponding (unique) products see A086860.
The number pairs are given by {a(n) -+ A086888(n)}/2.
Cf. A014092, A086473.

A086860 Numbers in A086473 corresponding to the unique product of two numbers having the unique sum of A086533.

Original entry on oeis.org

52, 244, 1168, 1776, 4672, 4192, 2608, 724, 8128, 916, 1912, 3328, 15424, 9952, 3352, 3592, 53632, 80128, 36352, 51712, 65152, 5272, 20512, 72832, 22432, 111756, 133888, 84352, 6472, 48448, 26272, 172288, 107392, 37480, 187648, 242496
Offset: 1

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Author

Lekraj Beedassy, Sep 12 2003

Keywords

Comments

Related to Martin Gardner's "Impossible Problem".
a(n) is thus a subsequence of A086473, itself a subsequence of A058080. Consider the mapping f:P->S defined thus: S is the sum of a factor pair (both different from 1) of P, where P is a(n). If S is A086533(n) (a subsequence of A014092), then both f and its inverse are injective (but not onto).

Crossrefs

Cf. A086533.

Extensions

Corrected by Ray Chandler, Oct 23 2003

A086472 Primes which are sum of two palindromes.

Original entry on oeis.org

2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 137, 139, 149, 157, 163, 167, 173, 179, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271, 277, 281, 283, 293, 307
Offset: 1

Views

Author

Amarnath Murthy, Jul 21 2003

Keywords

Comments

Many small primes are members. 43 is the first prime which is not a member.

Examples

			41 = 33 + 8, 47 = 44 + 3 are members but 43 is not.

Crossrefs

Cf. A086473.

Programs

  • Mathematica
    pal = Select[ Range[1000], FromDigits[ Reverse[ IntegerDigits[ # ]]] == # &];

Extensions

Edited, corrected and extended by Robert G. Wilson v, Jul 27 2003
Showing 1-3 of 3 results.

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