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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A323638 Nested square root sqrt(b(n) - sqrt(b(n-1) - ... - sqrt(b(1))...)), where b(n) = A323637(n).

Original entry on oeis.org

1, 1, 2, 1, 3, 1, 4, 2, 2, 3, 2, 4, 3, 3, 4, 4, 5, 2, 5, 3, 5, 4, 6, 3, 6, 4, 7, 3, 7, 4, 8, 4, 9, 4, 10, 4, 11, 5, 5, 6, 5, 7, 5, 8, 5, 9, 5, 10, 5, 11, 6, 6, 7, 6, 8, 6, 9, 6, 10, 6, 11, 7, 7, 8, 7, 9, 7, 10, 7, 11, 8, 8
Offset: 1

Views

Author

Ivan Neretin, Jan 21 2019

Keywords

Crossrefs

Cf. A323637.

A323635 Lexicographically earliest sequence of distinct positive integers such that the nested square root sqrt(a(n) + sqrt(a(n-1) + ... + sqrt(a(1))...)) is an integer.

Original entry on oeis.org

1, 3, 2, 7, 6, 13, 5, 22, 4, 33, 10, 12, 21, 11, 32, 19, 20, 31, 30, 43, 9, 45, 18, 44, 29, 58, 8, 60, 17, 59, 28, 75, 16, 76, 27, 94, 15, 95, 26, 115, 14, 116, 25, 138, 24, 163, 23, 190, 35, 42, 57, 41, 74, 40, 93, 39, 114, 38, 137, 37, 162, 36, 189, 50, 56, 73, 55, 92, 54, 113, 53, 136
Offset: 1

Views

Author

Ivan Neretin, Jan 21 2019, following a suggestion from Edward Turkevich

Keywords

Comments

A permutation of positive integers.

Crossrefs

Cf. A323636 (values of the square roots), A323637 (similar definition with minus).

Programs

  • PARI
    lista(nn) = {my(va = vector(nn), lastsq); va[1] = 1; lastsq = 1; for (n=2, nn, my(k = ceil(sqrt(sqrtint(lastsq)))); while (#select(x->(x==(k^2-sqrtint(lastsq))), va), k++); va[n] = k^2-sqrtint(lastsq); lastsq = k^2;); va;} \\ Michel Marcus, Oct 13 2020
Showing 1-2 of 2 results.