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.

A297164 Permutation of nonnegative integers: a(n) = A156552(A005940(1+n)-1).

Original entry on oeis.org

0, 1, 2, 3, 4, 7, 8, 5, 6, 17, 16, 23, 64, 65, 10, 9, 32, 19, 128, 129, 512, 67, 256, 47, 24, 4097, 20, 4099, 32768, 79, 1024, 11, 18, 31, 14, 29, 4096, 2049, 66, 515, 514, 263, 65536, 2053, 8388608, 524289, 16384, 87, 16777216, 2097153, 70, 524291, 17179869184, 287, 524288, 1037, 8388610, 289, 134217728, 1071, 520, 97, 38, 15, 12, 257, 8192, 63
Offset: 1

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Author

Antti Karttunen, Jan 05 2018

Keywords

Comments

Note the indexing: although the domain starts from 1, the range includes also zero.

Crossrefs

Inverse: A297163.
Cf. also A297166, A341520, A351960.

Programs

  • PARI
    A005940(n) = { my(p=2,t=1); n--; until(!n\=2, if(n%2, t*=p, p=nextprime(p+1))); t };
    A156552(n) = {my(f = factor(n), p, p2 = 1, res = 0); for(i = 1, #f~, p = 1 << (primepi(f[i, 1]) - 1); res += (p * p2 * (2^(f[i, 2]) - 1)); p2 <<= f[i, 2]); res}; \\ From A156552
    A297164(n) = A156552(A005940(1+n)-1); \\ Antti Karttunen, Feb 27 2022
  • Scheme
    (define (A297164 n) (A156552 (+ -1 (A005940 (+ 1 n)))))
    

Formula

a(n) = A156552(A005940(1+n)-1).