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.

User: Reed Michael Upson

Reed Michael Upson's wiki page.

Reed Michael Upson has authored 3 sequences.

A355460 Imaginary part of the Heighway/Harter dragon curve points which are on the imaginary axis.

Original entry on oeis.org

0, 1, 2, -3, -4, -5, -6, -9, -8, -9, -10, 11, 12, 13, 14, 17, 16, 15, 14, 19, 20, 21, 22, 25, 24, 25, 26, 37, 36, 35, 34, 31, 32, 31, 30, 35, 36, 37, 38, 41, 40, 41, 42, -43, -44, -45, -46, -49, -48, -47
Offset: 0

Views

Author

Reed Michael Upson, Jul 02 2022

Keywords

Comments

This sequence gives the values A332384(k) when A332383(k) = 0. - Rémy Sigrist, Oct 04 2022

Links

Crossrefs

Cf. A246960, A332383, A332384, A355459.

Programs

  • PARI
    See Links section.

A355459 Real part of the Heighway/harter dragon curve points which are on the real axis.

Original entry on oeis.org

0, 1, -2, -3, -4, -5, 6, 7, 8, 7, 10, 11, 12, 13, 18, 17, 16, 15, 18, 19, 20, 21, -22, -23, -24, -23, -26, -27, -28, -29, -34, -33, -32, -33, -30, -29, -28, -27, -38, -39, -40, -39, -42, -43, -44, -45, -50, -49, -48, -47
Offset: 0

Views

Author

Reed Michael Upson, Jul 02 2022

Keywords

Comments

This sequence gives the values A332383(k) when A332384(k) = 0. - Rémy Sigrist, Oct 04 2022

Links

Crossrefs

Cf. A246960, A332383, A332384, A355460.

Programs

  • PARI
    See Links section.

A355161 Primes p such that p - prevprime(p) is not a power of 2.

Original entry on oeis.org

29, 37, 53, 59, 67, 79, 89, 127, 137, 149, 157, 163, 173, 179, 191, 211, 223, 239, 251, 257, 263, 269, 277, 293, 307, 331, 337, 347, 359, 373, 379, 389, 419, 431, 439, 449, 479, 509, 521, 541, 547, 557, 563, 569, 577, 587, 593, 599, 607, 613
Offset: 1

Views

Author

Reed Michael Upson, Jun 21 2022

Keywords

Comments

A130796(n) is prevprime(p).
A031925 and A031931 are subsequences, as 6 and 12 are not powers of 2.

Crossrefs

Cf. A000079, A031925, A031931, A130796, A151800.

Programs

  • Mathematica
    Select[Prime[Range[2, 120]], (d = # - NextPrime[#, -1]) != 2^IntegerExponent[d, 2] &] (* Amiram Eldar, Jun 22 2022 *)
  • PARI
    isp2(n) = my(p); (n==1) || (isprimepower(n, &p) && (p==2)); \\ A000079
isok(p) = isprime(p) && !isp2(p-precprime(p-1)) \\ Michel Marcus, Jun 22 2022
  • Python
    from itertools import islice, count
from sympy import prime, prevprime
def A355161_gen(): # generator of terms
    return filter(lambda n:((~(m:=n-prevprime(n))+1)&m)-m, (prime(n) for n in count(2)))
A355161_list = list(islice(A355161_gen(),30)) # Chai Wah Wu, Aug 23 2022

Formula

a(n) = A151800(A130796(n)).

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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