The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A062332 Primes starting and ending with 1. 9
 11, 101, 131, 151, 181, 191, 1021, 1031, 1051, 1061, 1091, 1151, 1171, 1181, 1201, 1231, 1291, 1301, 1321, 1361, 1381, 1451, 1471, 1481, 1511, 1531, 1571, 1601, 1621, 1721, 1741, 1801, 1811, 1831, 1861, 1871, 1901, 1931, 1951, 10061, 10091, 10111, 10141 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Complement of A208261 (nonprime numbers with all divisors starting and ending with digit 1) with respect to A208262 (numbers with all divisors starting and ending with digit 1). - Jaroslav Krizek, Mar 04 2012 Intersection of A030430 and A045707. - Michel Marcus, Jun 08 2013 LINKS Harry J. Smith, Table of n, a(n) for n = 1..1000 FORMULA A010051(a(n)) * A000030(a(n)) * (a(n) mod 10) = 1. - Reinhard Zumkeller, Jul 16 2014 EXAMPLE 102701 is a member as it is a prime and the first and the last digits are both 1. MATHEMATICA fl1Q[n_]:=Module[{idn=IntegerDigits[n]}, First[idn]==Last[idn]==1]; Select[ Prime[Range[1300]], fl1Q] (* Harvey P. Dale, Apr 30 2012 *) PROG (PARI) { n=-1; t=log(10); forprime (p=2, 5*10^5, if ((p-10*(p\10)) == 1 && (p\10^(log(p)\t)) == 1, write("b062332.txt", n++, " ", p); if (n==1000, break)) ) } \\ Harry J. Smith, Aug 05 2009 (Haskell) a062332 n = a062332_list !! (n-1) a062332_list = filter ((== 1) . a010051') a208259_list -- Reinhard Zumkeller, Jul 16 2014 CROSSREFS Cf. A208259 (Numbers starting and ending with digit 1). Cf. A010051, A017281, A131835, A000030. Sequence in context: A316604 A208362 A159613 * A222723 A088281 A068685 Adjacent sequences:  A062329 A062330 A062331 * A062333 A062334 A062335 KEYWORD nonn,base,easy AUTHOR Amarnath Murthy, Jun 21 2001 EXTENSIONS Corrected and extended by Larry Reeves (larryr(AT)acm.org), Jun 29 2001 Missing term a(36)=1901 added by Harry J. Smith, Aug 05 2009 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified November 29 13:17 EST 2021. Contains 349416 sequences. (Running on oeis4.)