A260083 -id:A260083 - cp's OEIS frontend

A061364 Pseudo-random numbers: a (very weak) pseudo-random number generator from the second edition of the C book.

16838, 5758, 10113, 17515, 31051, 5627, 23010, 7419, 16212, 4086, 2749, 12767, 9084, 12060, 32225, 17543, 25089, 21183, 25137, 25566, 26966, 4978, 20495, 10311, 11367, 30054, 17031, 13145, 19882, 25736, 30524, 28505, 28394

Offset: 0

Frank Ellermann, Jun 11 2001

WATCOM C/C++ 10.0b uses this sequence for stdlib.h rand(). MS C 6.0 and gcc 2.6.3 use other (similar) sequences.

Brian W. Kernighan and Dennis M. Ritchie, The C Programming Language, Second Edition, ANSI C, 1988, Prentice-Hall Internat., ch. 2.7.
Brian W. Kernighan and Dennis M. Ritchie, The C-programming-language [German], 1990, Hanser, p. 45.

Harry J. Smith, Table of n, a(n) for n = 0..1000
Index entries for sequences related to pseudo-random numbers.

Cf. A096558, A221555, A221556, A221557, A221558, A221559, A221560, A221561, A221562, A260083.

A096554 is the same sequence seeded with 0.

unsigned long next= 1; int i= 0; while (i++ < 33) next= next * 1103515245 + 12345, printf( "%d ", (unsigned)( next/65536 ) %32768 );

x=1; m=2^32; for (n=0, 1000, x=(x*1103515245 + 12345)%m; write("b061364.txt", n, " ", (x\65536)%32768) ) \\ Harry J. Smith, Jul 21 2009

From David Fifield, May 23 2024: (Start)
a(n) = A096554(n+934703610).
a(n) = floor(A096553(n+2)/65536) mod 32768. (End)

A276820 Consecutive numbers generated by the 'random' function in PARI (64 bit, version > 2.4) using the default argument (2^31).

Original entry on oeis.org

1546275796, 879788114, 1745191708, 771966234, 1247963869, 1611845387, 1529973242, 2093650929, 1860635684, 1497261229, 1145234796, 1165293667, 1233809453, 785019983, 252606271, 111721893, 473031201, 1002808953, 614474799, 471414712, 65507668

Offset: 1

Hugo Pfoertner, Sep 18 2016

nonn

For comments, references and programs see A260083. Both the 32 bit and the 64 bit version of the random number generator have a period of 2^4096-1.

Hugo Pfoertner, Table of n, a(n) for n = 1..100
Richard P. Brent, Some long-period random number generators using shifts and xors, ANZIAM Journal 48 (CTAC2006), C188-C202, 2007.
PARI, Catalogue of GP/PARI Functions, Conversions and similar elementary functions or commands: random({N = 2^{{31}}})
Index entries for sequences related to pseudo-random numbers.

Cf. A260083, 32 bit version of this random number generator.

PARI
```
setrand(1); vector(100, i, random())
```

A357907 The internal state of the Sinclair ZX81 and Spectrum random number generator.

Original entry on oeis.org

1, 149, 11249, 57305, 38044, 35283, 24819, 26463, 18689, 25472, 9901, 21742, 57836, 12332, 7456, 34978, 1944, 14800, 61482, 23634, 3125, 37838, 19833, 45735, 22275, 32274, 61292, 9384, 48504, 33339, 10093, 36142, 23707, 8600, 55241, 14318, 25332, 64938, 20686, 44173, 36199, 27982

Offset: 1

Jacques Basaldúa, Oct 19 2022

The ZX81 had a congruential random number generator with the hardcoded values: x <- (75*x + 74) mod 65537.
This sequence starts with x = 1. The ZX81 had the option to start with a hardware counter.
The sequence has period 2^16. - Rémy Sigrist, Oct 20 2022
The ZX81 returned these values divided by 65536 as floating-point numbers, however, the seed was set as an integer using RAND (or RANDOMIZE on the ZX Spectrum). To produce the sequence as given here on the ZX81, set the seed with RAND 25340 (the last value in the period before it returns to 1), then print successive values with PRINT 65536*RND. On the ZX81, the current seed was stored in memory locations 16343 and 16384, and could be retrieved with PRINT 256*PEEK 16435+PEEK 16434 (which is equivalent to PRINT 65536*RND, but does not trigger stepping to the next value). - Sean A. Irvine, May 08 2025

Jianing Song, Table of n, a(n) for n = 1..65536
B. D. Ripley, Computer Generation of Random Variables: A Tutorial, International Statistical Review, 51 (1983), 301-309.
W. E. Sharp and Carter Bays, A review of portable random number generators, Computers and Geosciences, 18, 1 (1982), 79-87.
Wikipedia, Linear congruential generator.
Index entries for linear recurrences with constant coefficients, order 32769.
Index entries for sequences related to pseudo-random numbers.

Cf. A061364, A096550-A096561, A260083, A276820.

NestList[Mod[75*# + 74, 65537] &, 1, 50] (* Paolo Xausa, Oct 03 2024 *)

my(c=Mod(75,65537)); a(n) = lift(2*c^(n-1) - 1); \\ Kevin Ryde, Oct 22 2022

def a(n): return (2*pow(75, n-1, 65537) - 1)%65537
print([a(n) for n in range(1, 43)]) # Michael S. Branicky, Oct 23 2022

x <- 1
nxt <- function(x) (75*x + 74) %% 65537
for (t in 1:1000) {
  cat(sprintf('%i, ', x))
  x <- nxt(x)
}

a(n) = (75*a(n-1) + 74) mod 65537, a(1) = 1.
a(n + 2^16) = a(n). - Rémy Sigrist, Oct 20 2022
a(n) = (2*75^(n-1) - 1) mod 65537. - Kevin Ryde, Oct 20 2022
a(n) = a(n-1) - a(n-32768) + a(n-32769) for n > 32769. - Ray Chandler, Aug 03 2023

cp's OEIS Frontend

A061364 Pseudo-random numbers: a (very weak) pseudo-random number generator from the second edition of the C book.

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A276820 Consecutive numbers generated by the 'random' function in PARI (64 bit, version > 2.4) using the default argument (2^31).

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PARI

A357907 The internal state of the Sinclair ZX81 and Spectrum random number generator.

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