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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A134215 Positions of 15 after decimal point in decimal expansion of Pi.

Original entry on oeis.org

3, 314, 324, 344, 393, 730, 922, 1030, 1098, 1100, 1114, 1315, 1342, 1436, 1657, 2148, 2150, 2215, 2327, 2389, 2501, 2565, 2688, 2957, 3000, 3093, 3099, 3275, 3280, 3354, 3414, 3464, 3522, 3532, 3553, 3644, 3858, 3959, 4362, 4389, 4536, 4597, 4645, 4828, 4866
Offset: 1

Views

Author

Artur Jasinski, Oct 14 2007

Keywords

Crossrefs

Programs

  • Mathematica
    First /@ SequencePosition[RealDigits[Pi - 3, 10, 5000][[1]], {1, 5}] (* Amiram Eldar, Mar 20 2020 *)

Extensions

More terms from Amiram Eldar, Mar 20 2020

A134216 Positions of 16 after decimal point in decimal expansion of Pi.

Original entry on oeis.org

40, 68, 238, 396, 791, 992, 1130, 1182, 1206, 1324, 1410, 1422, 1504, 1602, 1610, 1651, 1709, 1767, 2142, 2185, 2345, 2352, 2402, 2459, 2640, 2746, 3024, 3220, 3370, 3399, 3409, 3516, 3529, 3535, 3585, 3650, 3660, 3860, 3978, 3994, 4128, 4342, 4385, 4648, 4653
Offset: 1

Views

Author

Artur Jasinski, Oct 14 2007

Keywords

Crossrefs

Programs

  • Mathematica
    First /@ SequencePosition[RealDigits[Pi - 3, 10, 5000][[1]], {1, 6}] (* Amiram Eldar, Mar 20 2020 *)

Extensions

More terms from Amiram Eldar, Mar 20 2020

A134217 Positions of 17 after decimal point in decimal expansion of Pi.

Original entry on oeis.org

95, 138, 155, 319, 342, 428, 438, 547, 566, 568, 574, 640, 646, 786, 850, 887, 889, 961, 1086, 1134, 1152, 1419, 1577, 1621, 1625, 1758, 1788, 1850, 1946, 2109, 2187, 2491, 2573, 2591, 2947, 3177, 3310, 3393, 3419, 3539, 3789, 4094, 4218, 4418, 4430, 4444, 4510
Offset: 1

Views

Author

Artur Jasinski, Oct 14 2007

Keywords

Crossrefs

Programs

  • Mathematica
    Flatten[Position[Partition[Rest[RealDigits[\[Pi],10,3000][[1]]],2,1], {1,7}]]  (* Harvey P. Dale, Apr 07 2011 *)

Extensions

More terms from Harvey P. Dale, Apr 07 2011
More terms from Amiram Eldar, Mar 20 2020

A134218 Positions of 18 after decimal point in decimal expansion of Pi.

Original entry on oeis.org

424, 446, 471, 490, 587, 728, 752, 797, 847, 951, 1035, 1056, 1225, 1444, 1539, 1572, 1574, 1674, 1715, 1738, 1897, 2220, 2628, 2776, 2867, 2942, 2964, 2989, 3082, 3149, 3318, 3339, 3343, 3439, 3549, 3596, 3607, 3664, 3801, 3922, 3956, 4044, 4070, 4145, 4179, 4485
Offset: 1

Views

Author

Artur Jasinski, Oct 14 2007

Keywords

Crossrefs

Programs

  • Mathematica
    First /@ SequencePosition[RealDigits[Pi - 3, 10, 5000][[1]], {1, 8}] (* Amiram Eldar, Mar 20 2020 *)

Extensions

More terms from Amiram Eldar, Mar 20 2020

A134219 Positions of 19 after decimal point in decimal expansion of Pi.

Original entry on oeis.org

37, 168, 198, 246, 390, 417, 432, 495, 541, 704, 717, 843, 945, 975, 985, 997, 1047, 1166, 1227, 1237, 1345, 1384, 1427, 1535, 1618, 1641, 1733, 1881, 1915, 1944, 2054, 2128, 2821, 2856, 2872, 2897, 2902, 2905, 2918, 2944, 2960, 2997, 3030, 3166, 3337, 3358
Offset: 1

Views

Author

Artur Jasinski, Oct 14 2007

Keywords

Crossrefs

Programs

  • Mathematica
    Transpose[SequencePosition[RealDigits[Pi,10,10000][[1]],{1,9}]][[1]]-1 (* The program uses the SequencePosition function from Mathematica version 10 *) (* Harvey P. Dale, May 09 2016 *)

A037024 Position of start of first occurrence of prime(n) after the decimal point in expansion of Pi.

Original entry on oeis.org

6, 9, 4, 13, 94, 110, 95, 37, 16, 186, 137, 46, 2, 23, 119, 8, 4, 219, 98, 39, 299, 13, 26, 11, 12, 852, 3486, 1487, 206, 362, 297, 1096, 859, 525, 2606, 393, 1657, 1410, 1182, 428, 438, 728, 1944, 168, 37, 704, 93, 135, 484, 185, 229, 1688, 1707, 1713, 1006
Offset: 1

Views

Author

Patrick De Geest, Jan 04 1999

Keywords

Examples

			Pi = 3.14159265358979323846264338327950288... (see A000796).
First occurrence of prime(23) = 83 starts at the 26th digit after the decimal point, hence a(23) = 26.
		

Crossrefs

Programs

  • Magma
    k:=3500; R := RealField(k); [ Position(IntegerToString(Round(10^k*(-3 + Pi(R)))), IntegerToString(NthPrime(n))) : n in [1..55] ]; /* Klaus Brockhaus, Feb 15 2007 */
    
  • Mathematica
    Module[{p = Rest[First[RealDigits[Pi, 10, 10^4]]], n = 0, a}, Reap[While[(a = SequencePosition[p, IntegerDigits[Prime[++n]], 1]) != {}, Sow[a[[1, 1]]]]][[2, 1]]] (* Paolo Xausa, Aug 01 2024 *)
  • Python
    from itertools import takewhile
    from sympy import S, prime, primerange
    # download https://stuff.mit.edu/afs/sipb/contrib/pi/pi-billion.txt, then
    # with open('pi-billion.txt', 'r') as f: pi_digits = f.readline()[1:]
    pi_digits = str(S.Pi.n(10**4))[1:] # alternative to above
    def aupton(nn):
        plocs = (pi_digits.find(str(p)) for p in primerange(2, prime(nn)+1))
        return list(takewhile(lambda x: x>=0, plocs)) # until p not found
    print(aupton(55)) # Michael S. Branicky, Jun 12 2021

Extensions

Edited by Klaus Brockhaus, Feb 15 2007

A038099 Numbers k such that k > first location of string of k in decimal expansion of Pi.

Original entry on oeis.org

4, 5, 9, 14, 15, 23, 26, 32, 33, 35, 38, 41, 43, 46, 50, 51, 53, 58, 59, 62, 64, 65, 69, 71, 74, 75, 78, 79, 81, 82, 83, 84, 86, 88, 89, 92, 93, 94, 95, 97, 98, 99, 105, 117, 132, 141, 148, 159, 164, 169, 170, 172, 174, 193, 197, 208, 209, 211, 214, 223, 229
Offset: 1

Views

Author

Patrick De Geest, Feb 15 1999

Keywords

Comments

'Location' starts from the first digit after the decimal point and refers to the first digit of a(n).

Crossrefs

Programs

  • Python
    from sympy import pi
    from itertools import count, islice
    digits_of_pi = str(pi.n(10**5))[1:-1]
    def agen():
        for k in count(1):
            kloc = digits_of_pi.find(str(k))
            assert kloc > 0, ("Increase precision", k)
            if k > kloc: yield k
    print(list(islice(agen(), 61))) # Michael S. Branicky, Jul 10 2022

Formula

a(n) > A014777(n). - Michael S. Branicky, Jul 10 2022

Extensions

Offset changed to 1 by Jinyuan Wang, Sep 04 2021

A038100 Numbers k such that k < first location of string of k in decimal expansion of Pi.

Original entry on oeis.org

0, 2, 3, 6, 7, 8, 10, 11, 12, 13, 16, 17, 18, 19, 20, 21, 22, 24, 25, 27, 28, 29, 30, 31, 34, 36, 37, 39, 40, 42, 44, 45, 47, 48, 49, 52, 54, 55, 56, 57, 60, 61, 63, 66, 67, 68, 70, 72, 73, 76, 77, 80, 85, 87, 90, 91, 96, 100, 101, 102, 103, 104, 106, 107, 108
Offset: 1

Views

Author

Patrick De Geest, Feb 15 1999

Keywords

Comments

'Location' starts from the first digit after the decimal point and refers to the first digit of a(n).

Crossrefs

Programs

  • Python
    from sympy import pi
    from itertools import count, islice
    digits_of_pi = str(pi.n(10**5))[1:-1]
    def agen():
        for k in count(0):
            kloc = digits_of_pi.find(str(k))
            assert kloc > 0, ("Increase precision", k)
            if k < kloc: yield k
    print(list(islice(agen(), 65))) # Michael S. Branicky, Jul 10 2022

Formula

a(n) < A014777(n). - Michael S. Branicky, Jul 10 2022

Extensions

Offset changed to 1 by Jinyuan Wang, Sep 04 2021

A103186 a(n) is the position of the start of the first occurrence of n > a(n-1) after the decimal point in Pi = 3.14159265358979323846264338327950288...

Original entry on oeis.org

1, 6, 9, 19, 31, 41, 47, 52, 55, 163, 174, 220, 281, 295, 314, 396, 428, 446, 495, 600, 650, 661, 698, 803, 822, 841, 977, 1090, 1124, 1358, 1435, 1501, 1667, 1668, 1719, 1828, 1926, 1968, 1987, 2007, 2161, 2210, 2236, 2261, 2305, 2416, 2509, 2555, 2595
Offset: 1

Views

Author

Suggested by Bob's Poetry Page. - Alonso del Arte, Mar 01 2005

Keywords

Comments

The digits at position 1667 are "334", so according to the strict definition of this sequence, a(33) is 1667 and a(34) is 1668. However, this would not enable a person to mark in bold-face the counting numbers within the digits of pi, which was the inspiration for this sequence. Surprisingly, if overlapping is not allowed, this changes only one element of the sequence. a(34) becomes 1700 and a(35) remains 1719. No other overlapping occurs within the first 100,000 decimal digits of Pi. - Graeme McRae, Mar 20 2005

Examples

			Moving always to the right in the decimal expansion of Pi, the string "1" is found at position 1 counting from the first digit after the decimal point, the string "2" is found at position 6, the string "3" at position 6, the string "4" at position 19, etc.
		

Crossrefs

Cf. A000796, A078197, A014777 (another version).

Programs

  • Magma
    k := 3000; R := RealField(k); S := IntegerToString(Round(10^k*(-3 + Pi(R)))); Q := []; d := 0; for n in [1..49] do p:= Position(S, IntegerToString(n)); d+:=p; Append(~Q, d); S := Substring(S, p+1, #S-p); end for; Q; /* Klaus Brockhaus, Feb 15 2007 */
    
  • Mathematica
    p = ToString[ FromDigits[ RealDigits[ N[Pi - 3, 2600]][[1]]]]; lst = {0}; Do[a = StringPosition[p, ToString[n], 1][[1, 1]]; AppendTo[lst, a + lst[[ -1]]]; p = StringDrop[p, a], {n, 49}]; Rest[lst] (* Robert G. Wilson v, Mar 19 2005 *)
  • PARI
    lista(nn, t=10^5) = {default(realprecision, t); my(d, k, v=digits(floor(Pi*10^t))); for(n=1, nn, d=digits(n); until(v[k+1..k+#d]==d, k++); print1(k, ", ")); } \\ Jinyuan Wang, Feb 18 2021

Extensions

More terms from Graeme McRae and Robert G. Wilson v, Mar 19 2005

A178707 Position of the start of the first occurrence of n (expressed in binary) after the binary point in the binary expansion of Pi.

Original entry on oeis.org

1, 3, 3, 11, 3, 16, 15, 11, 6, 3, 19, 16, 47, 15, 14, 11, 6, 25, 3, 60, 23, 19, 16, 91, 47, 76, 18, 15, 93, 14, 13, 11, 95, 6, 25, 43, 3, 126, 60, 144, 23, 58, 19, 393, 227, 16, 91, 207, 47, 63, 245, 76, 40, 18, 15, 103, 93, 114, 184, 14, 173, 13, 12, 11, 95
Offset: 0

Views

Author

Will Nicholes, Jun 06 2010

Keywords

Examples

			The first nonnegative integer is 0; its binary expansion is 0, which is found at the first digit after Pi's binary point; therefore the first term in the sequence is "1".
The sixth nonnegative integer is 5; its binary expansion is 101, which is found starting at the 16th digit after Pi's binary point; therefore the sixth term in the sequence is "16".
		

Crossrefs

Previous Showing 21-30 of 44 results. Next