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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A073514 Number of primes less than 10^n with initial digit 4.

Original entry on oeis.org

0, 3, 20, 139, 1069, 8747, 74114, 641594, 5661135, 50653546, 458352691, 4185483176, 38510936699, 356622729564, 3320632228693, 31067060521057, 291869049531878, 2752144407792176, 26035873192178041, 247025281876786013, 2349914303292170310, 22407593754131275705
Offset: 1

Views

Author

Shyam Sunder Gupta, Aug 14 2002

Keywords

Examples

			a(2)=3 because there are 3 primes up to 10^2 whose initial digit is 4 (namely 41, 43 and 47).
		

Crossrefs

Cf. A073509 to A073517, their sum is A006880.
For primes with initial digit d (1 <= d <= 9) see A045707, A045708, A045709, A045710, A045711, A045712, A045713, A045714, A045715; A073517, A073516, A073515, A073514, A073513, A073512, A073511, A073510, A073509

Programs

  • Mathematica
    f[n_] := f[n] = PrimePi[5*10^n] - PrimePi[4*10^n] + f[n - 1]; f[0] = 0; Table[ f[n], {n, 0, 13}]

Extensions

Edited and extended by Robert G. Wilson v, Aug 29 2002
a(20)-a(22) added by David Baugh, Mar 22 2015

A073515 Number of primes less than 10^n with initial digit 3.

Original entry on oeis.org

1, 3, 19, 139, 1097, 8960, 75290, 651085, 5735086, 51247361, 463196868, 4225763390, 38851672813, 359541975662, 3345924530873, 31288310624754, 293820812588401, 2769490109678920, 26191046215879444, 248421640738371325, 2362546444095790527, 22522418647770393663
Offset: 1

Views

Author

Shyam Sunder Gupta, Aug 14 2002

Keywords

Examples

			a(2)=3 because there are 3 primes up to 10^2 whose initial digit is 3 (namely 3, 31 and 37).
		

Crossrefs

Cf. A073509 to A073517, their sum is A006880.
For primes with initial digit d (1 <= d <= 9) see A045707, A045708, A045709, A045710, A045711, A045712, A045713, A045714, A045715; A073517, A073516, A073515, A073514, A073513, A073512, A073511, A073510, A073509

Programs

  • Mathematica
    f[n_] := f[n] = PrimePi[4*10^n] - PrimePi[3*10^n] + f[n - 1]; f[0] = 1; Table[ f[n], {n, 0, 12}]

Extensions

Edited and extended by Robert G. Wilson v, Aug 29 2002
a(21)-a(22) added by David Baugh, Mar 22 2015

A073516 Number of primes less than 10^n with initial digit 2.

Original entry on oeis.org

1, 3, 19, 146, 1129, 9142, 77025, 664277, 5837665, 52064915, 469864125, 4281198201, 39319600765, 363545360347, 3380562309312, 31590949437540, 296487794277035, 2793170342851930, 26402713858800478, 250324979315879678, 2379753569255122805, 22678735843184786383
Offset: 1

Views

Author

Shyam Sunder Gupta, Aug 14 2002

Keywords

Examples

			a(2)=3 because there are 3 primes up to 10^2 whose initial digit is 2 (namely 2, 23 and 29).
		

Crossrefs

Cf. A073509 to A073517, their sum is A006880.
For primes with initial digit d (1 <= d <= 9) see A045707, A045708, A045709, A045710, A045711, A045712, A045713, A045714, A045715; A073517, A073516, A073515, A073514, A073513, A073512, A073511, A073510, A073509

Programs

  • Mathematica
    f[n_] := f[n] = PrimePi[3*10^n] - PrimePi[2*10^n] + f[n - 1]; f[0] = 1; Table[ f[n], {n, 0, 13}]

Extensions

Edited and extended by Robert G. Wilson v, Aug 29 2002
a(21)-a(22) added by David Baugh, Mar 21 2015

A038812 Number of primes less than 1000n.

Original entry on oeis.org

168, 303, 430, 550, 669, 783, 900, 1007, 1117, 1229, 1335, 1438, 1547, 1652, 1754, 1862, 1960, 2064, 2158, 2262, 2360, 2464, 2564, 2668, 2762, 2860, 2961, 3055, 3153, 3245, 3340, 3432, 3538, 3638, 3732, 3824, 3923, 4017, 4107, 4203, 4291, 4392, 4494
Offset: 1

Views

Author

Keywords

Crossrefs

Programs

  • Mathematica
    Table[ PrimePi[ n*1000 ], {n, 1, 45}]
  • PARI
    a(n)=primepi(1000*n) \\ Charles R Greathouse IV, Apr 29 2015

Extensions

Edited and extended by Robert G. Wilson v, Jan 29 2003

A038813 Number of primes less than 10000n.

Original entry on oeis.org

1229, 2262, 3245, 4203, 5133, 6057, 6935, 7837, 8713, 9592, 10453, 11301, 12159, 13010, 13848, 14683, 15497, 16342, 17170, 17984, 18807, 19618, 20437, 21221, 22044, 22837, 23642, 24432, 25224, 25997, 26800, 27608, 28404, 29182, 29977
Offset: 1

Views

Author

Keywords

Crossrefs

Programs

  • Mathematica
    Table[ PrimePi[ n*10^4 ], {n, 1, 30}]
  • PARI
    a(n)=primepi(10000*n) \\ Charles R Greathouse IV, Apr 29 2015

Extensions

Edited and extended by Robert G. Wilson v, Jan 29 2003

A038814 Number of primes less than 100000n.

Original entry on oeis.org

9592, 17984, 25997, 33860, 41538, 49098, 56543, 63951, 71274, 78498, 85714, 92938, 100021, 107126, 114155, 121127, 128141, 135072, 142029, 148933, 155805, 162662, 169511, 176302, 183072, 189880, 196645, 203362, 210109, 216816, 223492, 230209
Offset: 1

Views

Author

Keywords

Crossrefs

Programs

  • Mathematica
    Table[ PrimePi[ n*10^5 ], {n, 1, 30}]
  • PARI
    a(n)=primepi(10^5*n) \\ Charles R Greathouse IV, Apr 29 2015

Extensions

Edited and extended by Robert G. Wilson v, Jan 29 2003

A038815 Number of primes less than n*10^6.

Original entry on oeis.org

78498, 148933, 216816, 283146, 348513, 412849, 476648, 539777, 602489, 664579, 726517, 788060, 849252, 910077, 970704, 1031130, 1091314, 1151367, 1211050, 1270607, 1329943, 1389261, 1448221, 1507122, 1565927, 1624527, 1683065
Offset: 1

Views

Author

Keywords

Crossrefs

Programs

  • Mathematica
    Table[ PrimePi[ n*10^6 ], {n, 1, 30}]
  • PARI
    a(n)=primepi(10^6*n) \\ Charles R Greathouse IV, Apr 29 2015

Extensions

Edited and extended by Robert G. Wilson v, Jan 29 2003

A038816 Number of primes less than n*10^7.

Original entry on oeis.org

664579, 1270607, 1857859, 2433654, 3001134, 3562115, 4118064, 4669382, 5216954, 5761455, 6303309, 6841648, 7378187, 7912199, 8444396, 8974458, 9503083, 10030385, 10555473, 11078937, 11601626, 12122540, 12642573
Offset: 1

Views

Author

Keywords

Crossrefs

Programs

  • Mathematica
    Table[ PrimePi[ n*10^7 ], {n, 1, 30} ]
  • PARI
    a(n)=primepi(10^7*n) \\ Charles R Greathouse IV, Apr 29 2015

Extensions

More terms from Robert G. Wilson v, Aug 27 2001
Edited and extended by Robert G. Wilson v, Jan 29 2003

A038817 Number of primes less than n*10^8.

Original entry on oeis.org

5761455, 11078937, 16252325, 21336326, 26355867, 31324703, 36252931, 41146179, 46009215, 50847534, 55662470, 60454705, 65228333, 69985473, 74726528, 79451833, 84163019, 88862422, 93547928, 98222287, 102886526, 107540122
Offset: 1

Views

Author

Keywords

Crossrefs

Programs

  • Mathematica
    Table[ PrimePi[ n*10^8 ], {n, 1, 22}]
  • PARI
    a(n)=primepi(10^8*n) \\ Charles R Greathouse IV, Apr 29 2015

Extensions

Edited and extended by Robert G. Wilson v, Jan 29 2003

A038818 Number of primes less than n*10^9.

Original entry on oeis.org

50847534, 98222287, 144449537, 189961812, 234954223, 279545368, 323804352, 367783654, 411523195, 455052511, 498388617, 541555851, 584570200, 627440336, 670180516, 712799821, 755305935, 797703398, 840000027, 882206716, 924324489
Offset: 1

Views

Author

Keywords

Crossrefs

Programs

  • Mathematica
    Table[ PrimePi[ n*10^9 ], {n, 1, 22}]
  • PARI
    a(n)=primepi(10^9*n) \\ Charles R Greathouse IV, Apr 29 2015

Extensions

Edited and extended by Robert G. Wilson v, Jan 29 2003
Previous Showing 21-30 of 140 results. Next