A156672 a(1)=2, a(n+1) is the smallest prime >= a(n) + sum of digits of a(n).

2, 5, 11, 13, 17, 29, 41, 47, 59, 73, 83, 97, 113, 127, 137, 149, 163, 173, 191, 211, 223, 233, 241, 251, 263, 277, 293, 307, 317, 331, 347, 367, 383, 397, 419, 433, 443, 457, 479, 499, 521, 541, 557, 577, 599, 631, 641, 653, 673, 691, 709, 727, 743, 757, 787

Offset: 1

Author

Juri-Stepan Gerasimov, Feb 13 2009

Keywords

• nonn
• base
• less

Comments

Heuristically, a(n) ~ kn log n for some k >= 4.5/log 10.

Examples

			2, 5(>4=2+2), 11(>10>5+5), 13(=13=11+1+1), 17(=17=13+1+3), 29(>25=17+1+7), etc.
		

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A156604.

Programs

Mathematica

NestList[NextPrime[#+Total[IntegerDigits[#]]-1]&,2,60] (* Harvey P. Dale, Mar 25 2025 *)

Extensions

Corrected by Charles R Greathouse IV, Mar 19 2010