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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A328045 a(n) = smallest m for which there is a sequence n = b_1 < b_2 < ... < b_t = m such that b_1^c_1*b_2^c_2*...*b_t^c_t is a fourth power, with all c_i < 4.

Original entry on oeis.org

0, 1, 4, 6, 4, 10, 9, 14, 15, 9, 18, 22, 20, 26, 21, 24, 16, 34, 27, 38, 25, 28, 33, 46, 30, 25, 39, 35, 36, 58, 40, 62, 42, 44, 51, 45, 36, 74, 57, 52, 49, 82, 50, 86, 55, 54, 69, 94, 54, 49, 63, 68, 65, 106, 70, 66, 64, 76, 87, 118, 75, 122, 93, 77, 64, 78
Offset: 0

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Author

Peter Kagey, Oct 02 2019

Keywords

Comments

a(n) = n if and only if n is a perfect square.
a(n) >= n + A300518(n) if n is not a perfect square.
a(n) <= A006255(n), and a(n) = A006255(n) except for when n is in A328218, a subsequence of A269045.

Examples

			For n = 1, a(1) = 1   with sequence 1                =  1^4.
For n = 2, a(2) = 4   with sequence 2^2 * 4          =  2^4.
For n = 3, a(3) = 6   with sequence 3^2 * 4   *  6^2 =  6^4.
For n = 4, a(4) = 4   with sequence 4^2              =  2^4.
For n = 5, a(5) = 10  with sequence 5   * 8^3 * 10^3 = 40^4.
For n = 6, a(6) = 9   with sequence 6^2 * 8^2 *  9   = 12^4.
For n = 7, a(7) = 14  with sequence 7^2 * 8^2 * 14^2 = 28^4.
		

Crossrefs

Cf. A006255 (square), A277494 (cube).
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