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.

Showing 1-5 of 5 results.

A083712 Duplicate of A082806.

Original entry on oeis.org

2, 3, 5, 7, 11, 101, 131, 151, 191, 313, 353, 373, 757, 797, 919, 10301, 10501, 11311
Offset: 1

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Author

Keywords

A083184 Smallest palindromic prime having a sum of digits = prime(n), or 0 if no such number exists.

Original entry on oeis.org

2, 3, 5, 7, 191, 373, 13931, 757, 797, 19991, 77377, 77977, 79997, 1987891, 3799973, 7977797, 9889889, 9989899, 769797967, 797898797, 779999977, 37898989873, 39988988993, 78899799887, 99998989999, 3799999999973, 3998999998993
Offset: 1

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Author

Amarnath Murthy and Meenakshi Srikanth (menakan_s(AT)yahoo.com), Apr 26 2003

Keywords

Comments

Conjecture: no entry is zero.
Corresponds to first entry of A082806 with digit sum = n-th prime, A000040(n). - Lekraj Beedassy, May 23 2005

Crossrefs

Cf. A083183.

Extensions

Corrected and extended by Patrick De Geest, Jun 12 2003

A109830 Palindromic primes with both the number of digits and the digit sum also palindromic primes.

Original entry on oeis.org

11, 101, 131, 151, 191, 313, 353, 10301, 10501, 11311, 13331, 30103, 1003001, 1123211, 1201021, 1221221, 1303031, 1311131, 3001003, 3103013, 10000500001, 10000900001, 10002520001, 10013131001, 10111311101, 10301110301
Offset: 1

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Author

Zak Seidov, Jul 04 2005

Keywords

Crossrefs

Cf. A082806 = palindromes which are prime and the sum of the digits is also prime. A082806 = palindromic primes with a prime digit sum.

Extensions

More terms from Joshua Zucker, May 17 2006

A222116 Palindromic primes whose sum of digits is also a palindromic prime.

Original entry on oeis.org

2, 3, 5, 7, 11, 101, 131, 151, 191, 313, 353, 10301, 10501, 11311, 13331, 30103, 1003001, 1123211, 1201021, 1221221, 1303031, 1311131, 3001003, 3103013, 100030001, 100050001, 100111001, 100131001, 101030101, 110111011, 110232011, 111010111, 111050111
Offset: 1

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Author

Jayanta Basu, May 13 2013

Keywords

Examples

			353, a palindromic prime, is in the list since 3+5+3=11 is also a palindromic prime.
		

Crossrefs

Intersection of A082806 and A082208.

Programs

  • Mathematica
    palQ[n_]:=FromDigits[Reverse[IntegerDigits[n]]]==n; t={}; Do[If[palQ[p=Prime[n]] && palQ[td=Total[IntegerDigits[p]]] && PrimeQ[td],AppendTo[t,p]],{n,6400000}]; t

A230255 Emirps whose sum of digits is prime.

Original entry on oeis.org

113, 157, 179, 199, 311, 337, 359, 733, 739, 751, 937, 953, 971, 991, 1031, 1033, 1091, 1097, 1103, 1109, 1181, 1213, 1217, 1231, 1237, 1259, 1279, 1301, 1321, 1381, 1439, 1453, 1471, 1499, 1523, 1583, 1619, 1657, 1723, 1741, 1811, 1831, 1901, 1949, 3011, 3019
Offset: 1

Views

Author

K. D. Bajpai, Oct 14 2013

Keywords

Examples

			a(6)= 337 is emirp. Sum of digits= 3+3+7= 13 which is prime.
a(11)= 937 is emirp. Sum of digits= 9+3+7= 19 which is prime.
		

Crossrefs

Cf. A006567 (emirps: primes whose reversal is different prime).
Cf. A082806 (palindromic primes: sum of digits is prime).
Cf. A178092 (emirps: digital sum is emirp).

Programs

  • Maple
    with(StringTools):KD:= proc() local a,b,d; a:=ithprime(n);b:=parse(Reverse(convert(a,string))); d:=add( i,i = convert((a), base, 10))(a);if a<>b and isprime(b) and isprime(d) then return(a):fi; end: seq(KD(),n=1..2000);
  • Mathematica
    Select[Prime[Range[500]],!PalindromeQ[#]&&AllTrue[{IntegerReverse[#],Total[ IntegerDigits[ #]]},PrimeQ]&] (* Harvey P. Dale, Nov 01 2022 *)
Showing 1-5 of 5 results.