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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A382148 Index of first occurrence of n in A381238, or -1 if n does not appear there.

Original entry on oeis.org

0, 14, 1, 3, 79, 11, 30, 8, 108, 17, 6, 111, 169, 18, 76, 78, 74, 388, 239, 86, 383, 345, 191, 1017, 178, 486, 163, 1828, 209, 364, 484, 582, 160, 289, 436, 878, 174, 320, 37, 1029, 698, 1386, 768, 618, 558, 212, 1318, 2213, 826, 350, 877, 1780, 1033, 407, 188, 229, 1478, 467, 305
Offset: 1

Views

Author

N. J. A. Sloane, Mar 17 2025

Keywords

Crossrefs

Cf. A381238.

Programs

  • Mathematica
    b[n_] := b[n] = Sec[b[n-1]]^2; b[0] = 1; With[{v = Floor[Array[b, 600, 0]]}, -1 + TakeWhile[FirstPosition[v, #] & /@ Range[Max[v]], ! MissingQ[#] &] // Flatten] (* Amiram Eldar, Mar 18 2025 *)

Extensions

More terms from Amiram Eldar, Mar 18 2025
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