A156614 a(1)=2, a(n+1) is the smallest prime with sum of even digits >= sum of even digits of a(n).

2, 23, 29, 41, 43, 47, 61, 67, 83, 89, 181, 263, 269, 281, 283, 461, 463, 467, 487, 661, 683, 863, 881, 883, 887, 1889, 2683, 2687, 2689, 2861, 2887, 4861, 4889, 6689, 6863, 6869, 6883, 8681, 8689, 8861, 8863, 8867, 8887, 26881

Offset: 1

Author

Juri-Stepan Gerasimov, Feb 11 2009

Keywords

• nonn
• base
• less

Comments

An increasing sequence of primes a(n) such that the sequence A071648(a(n)) is nondecreasing. - R. J. Mathar, May 15 2010

Examples

			2, 23(2=2), 29(2=2), 41(4>2), 43(4=4), 61(6>4), 67(6=6), 83(8>6), 89(8=8), 181(8=8), 263(2+6=8), 269(2+6=2+6), 281(2+8>2+6), 283(2+8=2+8), 461(4+6=2+8), etc.
		

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..100

Crossrefs

Cf. A000040.

Programs

Mathematica

t={}; max=0; Do[p=Prime[i]; If[(x=Total[Select[IntegerDigits[p],EvenQ[#] &]])>=max, max = x; AppendTo[t,p]],{i,3000}]; t (* Jayanta Basu, May 22 2013 *)
sped[p_]:=Module[{d1=Total[Select[IntegerDigits[p],EvenQ]],p2=NextPrime[p]},While[ Total[ Select[ IntegerDigits[ p2],EvenQ]]Harvey P. Dale, Jan 22 2024 *)

Extensions

Corrected (4861 inserted) by R. J. Mathar, May 15 2010